Table Of ContentR. Nickel, A. Schummer, E. Seiferle
The Anatomy of the Domestic Animals
Volume 3
The Circulatory System, the Skin,
and the Cutaneous Organs
of the Domestic Mammals
The Anatomy
of the
Domestic Animals
founded by Richard Nickel, August Schummer, and Eugen Seiferle
Volume 1: The Locomotor System of the Domestic Mammals
by Richard Nickel, August Schummer, Eugen Seiferle,
Josef Frewein, and Karl-H. Wille (prob. published 1983)
Volume 2: The Viscera of the Domestic Mammals
by August Schummer, Richard Nickel, and Wolfgang
Otto Sack, 2nd revised Ed. 197 9
Volume 3: The Circulatory System, the Skin, and the Cutaneous
Organs of the Domestic Mammals
by August Schummer, Helmut Wilkens, Bernd Voll
merhaus, and Karl-H. Habermehl. Translation by
Walter G. Siller and Peter A. L. Wight 1981
Volume 4: The Nervous System, the Endocrine Glands, and the
Sensory Organs of the Domestic Mammals
by Eugen Seiferle (prob. published 1984)
Volume 5: Anatomy of the Domestic Birds
by August Schummer. Translation by Walter G. Siller
and Peter A. L. Wight 1977
Springer-Verlag Berlin Heidelberg GmbH
The Circulatory System,
the Skin,
and the Cutaneous Organs
of the Domestic Mammals
by August Schummer, Helmut Wilkens,
Bernd Vollmerhaus, and Karl-Heinz Habermehl
Translation
by Walter G. Siller and Peter A. L. Wight
With 439 illustrations, 173 in colour
1981
[$]
Springer-Verlag Berlin Heidelberg GmbH
This volume is an authorized translation of R. Nickel, A. Schummer, E. Seiferle (Ed.), Lehrbuch der Anatomie der Haustiere (The
Anatomy of the Domestic Animals), Volume 3: Kreislaufsystem, Haut und Hautorgane (The Circulatory System, the Skin, and the
Cutaneous Organs of the Domestic Mammals) by A. Schummer, H. Wilkens, B. Vollmerhaus, and K.-H. Habermehl, © 1976. Verlag
Paul Parey, Berlin and Hamburg, Germany.
Richard Nickel t, Dr. med. vet., Professor and Head of the Department of Anatomy, Tieraerztliche Hochschule Hanover,
D-3000 Hanover, Germany
August Schummer t, Dr. med. vet., Professor and Head of the Department of Veterinary Anatomy, Justus-Liebig-Universitaet
Giessen, D-6300 Giessen, Germany
Eugen Seiferle, Dr. med. vet., Dr. med. vet. h. c., Professor and Head of the Department of Veterinary Anatomy, Universitaet
Zurich, CH-8057 Zurich, Switzerland
Helmut Wilkens, Dr. med. vet., Professor and Head of the Department of Anatomy, Tieraerztliche Hochschule Hanover,
D-3000 Hanover, Germany
Bernd Vollmerhaus, Dr. med. vet., Professor and Head of the Department of Veterinary Anatomy, Ludwig-Maximilians-Universitaet
Munich, D-8000 Munich, Germany
Karl-Heinz Habermehl, Dr. med. vet., Professor and Head of the Department of Veterinary Anatomy, Justus-Liebig-Universitaet
Giessen, D-6300 Giessen, Germany
Walter G. Siller, Dr. med. vet., Ph. D., M.R.C.V.S., F.R.C. Path., F.R.S.£., Universiry of Edinburgh
Peter A. L. Wight, F.R.C.V.S., Ph. D., D.V.S.M., F.R.C. Path., F.R.S.£., Universiry of Edinburgh
Synopsis of the English edition: The Anatomy of the Domestic Animals
Volume I: Locomotor System of the Domestic Mammals. By R. Nickel, A. Schummer, E. Seiferle, J. Frewein, and K.-H. Wille.
Translation from the German. Approx. 560 pages, with about 517 illustrations in the text and on II colour plates. In preparation
Volume 2: The Viscera of the Domestic Mammals. By A. Schummer, R. Nickel, and W. 0. Sack. 2nd revised edition. Translated and
revised from the 4th German edition. 1979. 446 pages, with a total of 559 illustrations in the text and on 13 colour plates
Volume 3: The Circulatory System, the Skin, and the Cutaneous Organs of the Domestic Mammals. By A. Schummer, H. Wilkens,
B. Vollmerhaus, and K.-H. Habermehl. Translated from the German by W. G. Siller and P. A. L. Wight. 1981. 630 pages, with a
total of 439 illustrations, 173 in colour
Volume 4: Nervous System, Sensory Organs, Endocrine Glands of the Domestic Mammals. By E. Seiferle. Translation from the Ger
man. Approx. 442 pages, with a total of about 250 illustrations, about 95 in colour, in the text and on 10 colour plates. In preparation
Volume 5: Anatomy of the Domestic Birds. By A. Schummer. Translated from the German by W. G. Siller and P. A. L. Wight.
1977. 214 pages, with 141 illustrations in the text and on 7 colour plates
Synopsis of the German edition: Lehrbuch der Anatomie der Haustiere
Volume I: Bewegungsapparat. By R. Nickel, A. Schummer, E. Seiferle, J. Frewein, and K.-H. Wille. 4th revised edition. 1977.
560 pages, with a total of 517 illustrations in the text and on II colour plates
Volume II: Eingeweide. By A. Schummer and R. Nickel. 4th edition. 1979. 446 pages, with a total of 559 illustrations in the text and
on 13 colour plates
Volume III: Kreislaufsystem, Haut und Hautorgane. By A. Schummer, H. Wilkens. B. Vollmerhaus, and K.-H. Habermehl. 1976.
662 pages, with a total of 439 illustrations, 172 in colour
Volume IV: Nervensystem, Sinnesorgane, Endokrine Drusen. By E. Seiferle. 1975. 442 pages, with a total of 250 illustrations, 95 in
colour in the text and on I 0 colour plates
Volume V: Anatomie der Hausviigel. By A. Schummer. 1973. 215 pages, with a total of 141 illustrations in the text and on 7 colour
plates
CIP-Kurztitelaufnahme der Deutschen Bibliothek
Nickel, Richard: The circulatory system, the skin and the cutaneous
The anatomy of the domestic animals I founded by organs of the domestic mammals I by Au~st
Richard Nickel, August Schummer, and Eugen Schummer ... Trans!. by Walter George S1ller and
Seiferle. - Berlin ; Hamburg : Parey Peter Albert Laing Wight. - Berlin ; Hamburg :
Dt. Ausg. u.d.T.: Nickel, Richard: Lehrbuch der Par_9., 1981.
Anatomie der Haustiere. -Vol. 2 u. 5 erschienen (The anatomy of the domestic animals I founded
nicht als Teil d. Gesamtwerks by Richard Nickel, August Schummer, and Eugen
Seiferle ; Vol. 3)
NE: Schummer, August: ; Seiferle, Eugen: ISBN 978-0-387-91193-9
Vol. 3. ->The circulatory system, the skin and
NE: Schummer, August [Mitverf.]
the cutaneous organs of the domestic mammals
Cover design: Christian Honig, D-5450 NeuwiediRhein, Germany _ _ ..
This work is subject to copyright. All rights are reserved, whether the whole or part of the matenal1s conce~ned, spe~1f1cally th?se
rights of translation, reprinting, re-use of illustrations, recitation, broadcasting, reproduction by photocopymg machme or s1mliar
means, and storage in data banks. Under § 54, I of the German Copyright Law where single copies are made _for other than _pnvate
use, a fee is payable to the publisher according to§ 54,2 of the German Copyright Law. The amount of the fee IS to be determmed by
agreement with the publisher.
© 1981 by Springer-Verlag Berlin Heidelberg
Originally published by Verleg Paul Parey, Berlin and Hamburg in 19BI
Softcover reprint of the hardcover 1st edition 1981
ISBN 978-0-387-91193-9 ISBN 978-1-4899-7102-9 (eBook)
DOI 10.1007/978-1-4899-7102-9
Dedicated to the memory of
Richard Nickel
Richard Nickel (1905-1964), Dr. med. vet. habil., Dipl.-Landwirt,
Professor of Veterinary Anatomy, Histology and Embryology at Hanover 1948-1964
Translators' preface
The publication of this translated volume provides English versions of three of the five books which
comprise the "Lehrbuch der Anatomie der Haustiere". Some revision was necessary in the English
edition of the second volume largely to adapt the nomenclature, but this was not required in the
present book in which terms listed in the Nomina Anatomica Veterinaria were used in the original
German text. This is, therefore, an unrevised, unabridged translation which follows faithfully the
German text. As in the English version of Volume V, translated by ourselves, the Latin terminology is
used the first time a name occurs but subsequently the Englisch equivalent is generally substituted.
It should be pointed out that some of the breeds of farm animals mentioned may not be well known
outside their native Central Europe, but descriptions of many of them can be found in Mason, I. L.
(1951) "A world dictionary of breeds, types and varieties of livestock," Commonwealth Agricultural
Bureau, England.
In the chapter on the lymphatic organs, many references will be found to meat inspection and the
German legal requirements for the examination of lymph nodes in the abatoir. We were in some doubt
whether these should be omitted from the English edition because obviously legislation is not identical
in all countries. However, it was decided to retain them because they may be found useful as a general
guide but it must be remembered that they are based on the German regulations.
It is our pleasant duty to acknowledge the invaluable advice on the integument given by Dr. W. M.
Stokoe of the Department of Anatomy, Faculty of Veterinary Medicine, University of Edinburgh, and
Dr. M. L. Ryder of the Agricultural Research Council's Animal Breeding Research Organisation,
Edinburgh. We would also like to thank Mrs. Kathleen Wight for the accurate preparation of the
typescript. Finally, we must thank Dr. F. Georgi and his staff at the publishing house Paul Parey,
Berlin, for their patience and friendly consideration.
Edinburgh, March, 1981. W. G. Siller and P. A. L. Wight.
Preface to the German Edition
The publication of volume III completes the five-volume Textbook of Anatomy of Domestic
Animals.
The authors of the chapter on the blood vascular system are Professor A. Schummer of Giessen
(blood vessels -general considerations, blood and heart) and Professor H. Wilkens of Hanover (blood
vessels-arterial and venous systems). The section on the lymphatic system was compiled by Professor
B. Vollmerhaus of Munich and that on the skin and cutaneous organs was written by Professor K.-H.
Habermehl of Giessen. Dr. W. Munster of Hanover also contributed to the section on arteries and
vems.
This summarizes the general content of volume III in which the individual species of animals are
treated according to the same basic principle as in the previous volumes.
The introductory chapter discusses the cardiovascular system in a general way because the clinical
VIII Preface to the German Edition
diagnosis of pathological conditions depends on a thorough knowledge of the entire system. The
formation, composition, function and destruction of the blood are dealt with and this is followed by a
discourse on the structure and function of the blood vessels, including their nervous and hormonal
control. The description of the heart follows the same scheme, the first part dealing with fundamental
cardiac anatomy applicable to all mammals while subsequently consideration is given to species
peculiarities and the comparative characteristics of the organ.
In describing the origin, course and topography of the blood vessels it was important to include all
pertinent detail and yet avoid too lengthy a text. This could only be achieved by a comparative
presentation of the vessels of all species, region by region. This chosen method also served to
emphasize the fact that in each region the organization and distribution of the blood vessels is
basically similar in all species, thus allowing rules of nomenclature to be established for individual
blood vessels. Once this fundamental concept is understood, it is possible to extract all the desired
information about any one species from the descriptive text and illustrations. The principle is used
throughout except in the blood vessels of the foot where, because of the obvious differences in the
structure of the extremities, it is necessary to give a detailed description for each species of animal.
The discussion on the function of the lymphatic system is appropriate to the importance of this
subject, because much current research on it is of great medical interest. For this reason it seemed
advisable to record the present ( 1975) state of our knowledge in this field, although we are well aware
that theories are more quickly outdated in this area than in other medical disciplines. In accord with
the general principal of the book, the systematic description of the lymphatic organs in the various
species has been compiled so as to provide both basic knowledge and information of value in
veterinary practice.
The fundamental descriptions of Baum and his students and the more recent investigations of other
authors proved of great service in compiling this chapter. Numerous valuable illustrations from older
monographs, long out of print, were reproduced by kind permission of Springer Verlag.
As befits the importance of the carnivores, pig and ruminants, these species are dealt with more
liberally in the chapter on skin and the cutaneous organs than has been the custom in previous
textbooks of anatomy. Particular stress is placed on the account of special skin glands which are of
great importance as scent, marker and signal glands in conspecific communication.
We had numerous collaborators in the Institutes of Veterinary Anatomy in the Universities of
Giessen and Munich and of the Veterinary School of Hanover and we thank them all for their valuable
assistance.
Our thanks go to Mrs. V. Gube of Giessen for illustrating the chapters on the heart and skin and
cutaneous organs, which she accomplished with the artistic skill, understanding and insight for which
she is well known. We also thank Mrs. S. Pletscher of Zurich for some illustrations in the section on
the hoof. Dr. K.-H. Wille of Giessen provided expert criticism and correction of these chapters and,
last but not least, we are grateful to the secretary of the Institute at Giessen, Miss H. Seip, for the
careful preparation of the typescript.
We thank Mrs. R. Rochner, Mr. W. Heinemann and Mr. G. Kapitzke of Hanover for the careful
graphic work and exemplary artistic illustrations to the chapters on the blood vascular system and the
skin and cutaneous organs. We thank M.-L. Meinecke for the conscientious typing and Mrs. G. Voigt
and many other members of the institute for their help. We are grateful to Professor Dr. Wissdorf for
his valuable and stimulating cooperation.
We are indebted in Munich to Mrs. L. Korner for the drawings, to Dr. H. Roos, Dr. B.
Hossenfeldner, Dr. H. Waibl and Dr. H. E. Konig for their valuable help in preparing the list of
contents and the index and for proof-reading. Our thanks also go to Mrs. A. Speiser and Miss Ch.
Drechsler for typing the manuscript.
It is largely due to the constant and personal interest of Dr. Friedrich Georgi, a proprietor of the
publishing house, that this third volume, and, indeed, the whole project, was so satisfactorily
completed. He had great patience and understood the problems which confronted the authors. Our
special thanks are likewise extended to Mr. E. Topschowsky, manager of the publishing house, whose
vast experience spanning many decades, contributed considerably to the outstandingly high standard of
the book.
We hope that this third volume will be as well received as those which preceded it.
Giessen, Hanover, Munich August Schummer, Karl-Heinz Habermehl,
Summer 1976 Helmut Wilkens, Bernd Vollmerhaus
Contents
Page
Organs of the circulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Bloodvascular system ........................................................... .
Blood (A. Schummer, Giessen) ................................................ .
Blood plasma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Blood cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Erythrocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Leucocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Granulocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Monocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Lymphocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Thrombocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Organs of the haematopoiesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Development of blood cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Blood vessels, structure and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Arteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Veins . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Capillaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Arteriovenous anastomoses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Nutrition of the vessel wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Innervation of the blood vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Hormones acting on the blood vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Heart 15
Pericardium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Conformation of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Position of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Tissue components of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
The skeleton of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Architecture of the heart musculature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
The chambers of the heart and their internal structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
The atria of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Right atrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Left atrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
The ventricles of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Right ventricle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Left ventricle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Excitation and conducting system of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Innervation of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
X Contents
Blood vessels of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Arteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Veins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Structure and special organization of the blood vessels of the heart . . . . . . . . . . . . . . 40
Lymph vessels of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Species characteristic of the heart, general considerations . . . . . . . . . . . . . . . . . . . . . . . . . 41
Size, weight and measurements of the heart, general consideration . . . . . . . . . . . . . . . . . 41
The heart of the dog and the cat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Interior of the ventricles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Size and weight of the dog's heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Position of the heart in the dog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Heart of the cat, size and weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Blood vessels of the heart of the dog and cat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Arteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Veins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Heart of the pig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Internal structure of the ventricles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Size and weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Position of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Blood vessels of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Arteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Veins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Heart of the ox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Internal structure of the ventricles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Size and weight of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Heart of the sheep and goat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Internal structure of the ventricles (sheep) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Size, weight and position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Blood vessels of the hearts of ruminants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Arteries of the heart of the ox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Veins of the heart of the ox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Heart of the horse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Internal structure of the ventricles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Size and weight of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Position of the heart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Blood vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Arteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Veins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Species-diagnostic features of the hearts of domestic mammals . . . . . . . . . . . . . . . . . . . . . 68
Dog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Pig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Sheep and goat ...................................................... :. . 69
Ox . . . .. .. .. . . .. . . .. . . .. . ... . ........... .... .... ... . ... . . ... . ... . . .. . . 70
Horse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Arteries (arteriae) (H. Wilkens in collaboration with W. Munster, Hanover) . . . . . . . . . . . 71
Truncus pulmonalis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Aorta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
