Figure and Animal Drawing by Cecil G. Trew.
From the first chapter:
THE study of the human figure and the study of animals have so much in common from the artist's point of view that they may well be considered together. In fact the artist will gain much in both branches of his art if he recognizes their similarities and allows his knowledge of the one to aid him in the other. Even portraiture is only to a very limited extent an exception to this tenet.
Character and individuality should be aimed at in animal drawing as much as in portraying a human being, though in the case of the former we have a narrower range of possibility. Civilization has, so far, reached its peak in the evolution of what we call Modern Man. Man has developed a greater complexity of emotion than any other creature, and his desire to express his feelings and thoughts to his fellows has brought about a most intricate code of emphasis and gesture. An animal is capable of all the elemental emotions that sway a human being, such as fear, hatred, love, despondency and joy, but as a general rule these passions are more transitory in an animal and, being born of natural circumstances rather than complicated reasoning, leave less lasting effect on the physiognomy.
So far as the general anatomy of man and beast goes one cannot do better than to study them together, and when one remembers that, in bygone ages, man used to go on all fours, had a "hide that was covered with hair" and "talked" as do the beasts of the field, the likeness that his general structure still shows to that of all other warm-blooded animals is not to be wondered at.
The Artist's Guide to Animal Anatomy
The Artist's Guide to Human Anatomy
These images are from a different book, Horse Anatomy
by Lewis S. Brown.
Horse anatomy: A handbook for artists, comprising the study of the proportion, structure and action of the horse as compared to man
Horse Anatomy (Dover Pictorial Archive)
A plate from the original edition and the cover of a new edition of The Anatomy of the Horse by George Stubbs.
An Atlas of Animal Anatomy for Artists
Here is a similar book from 1860, A Comparative View of the Human and Animal Frame by Benjamin Waterhouse Hawkins. And a post with lots of reproductions at BibliOdyssey.
The whole book is on view at the University of Wisconsin History of Science site.
Other books by Benjamin Waterhouse Hawkins at Amazon.com:
The Artistic Anatomy of the Dog and Deer: With Illustrations Drawn on Wood by the Author
The Artistic Anatomy of the Horse: With 24 Illustrations on Wood by the Author
The Dinosaurs of Waterhouse Hawkins: An Illuminating History of Mr. Waterhouse Hawkins, Artist and Lecturer