354 ON THE STUDY OF ZOOLOGY 



the biologists have come to repudiate any blood-relationship 

 with their foster-brothers, the mineralogists. 



Certain broad laws have a general application throughout 

 both the animal and the vegetable worlds, but the ground 

 common to these kingdoms of nature is not of very wide 

 extent, and the multiplicity of details is so great, that the 

 student of living beings finds himself obliged to devote his 

 attention exclusively either to the one or the other. If 

 he elects to study plants, under any aspect, we know at 

 once what to call him. He is a botanist, and his science 

 is botany. But if the investigation of animal life be 

 his choice, the name generally applied to him will vary 

 according to the kind of animals he studies, or the par- 

 ticular phenomena of animal life to which he confines 

 his attention. If the study of man is his object, he is 

 called an anatomist, or a physiologist, or an ethnologist ; 

 but if he dissects animals, or examines into the mode in 

 which their functions are performed, he is a comparative 

 anatomist or comparative physiologist. If he turns 

 his attention to fossil animals, he is a paleontologist. 

 If his mind is more particularly directed to the specific 

 description, discrimination, classification, and distribution 

 of animals, he is termed a zoologist. 



For the purpose of the present discourse, however, I shall 

 recognise none of these titles save the last, which I shall 

 employ as the equivalent of botanist, and I shall use the 

 term zoology as denoting the whole doctrine of animal life, 

 in contradistinction to botany, which signifies the whole 

 doctrine of vegetable life. 



Employed in this sense, zoology, like botany, is divisible 

 Into three great but subordinate sciences, morphology, 

 physiology, and distribution, each of which may, to a very 

 great extent, be studied independently of the other. 



Zoological morphology is the doctrine of animal form or 

 struct ure. Anatomy is one of its branches ; development 

 is another ; 'while classification is the expression of the 

 relations which different animals bear to one another, in 

 respect of their anatomy and their development. 



Zoological distribution is the study of animals in relation 

 to the terrestrial conditions which obtain now, or have 

 obtained at any previous epoch of the earth's history. 



Zoological physiology, lastly, is the doctrine of the 

 functions or actions of animals. It regards animal bodies 

 as machines impelled by certain forces, and performing an 



