4 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



What does the examination of a structure tell us ? It 

 tells us the mode in which the various parts of the animal 

 or plant are arranged, and the special features which 

 characterise their appearance. It tells us to what extent 

 construction resembles or differs in the various animals 

 and plants. It tells us the changes which occur in the 

 character and form of the whole or of special parts as these 

 develop from the first stage of their existence and grow. 

 From such records we infer the relationship of a structure 

 or an animal to its contemporaries and even to forms 

 which once existed in the past. The genius of Darwin 

 and his successors has awakened so intense an interest 

 in the working out of these relationships that recent 

 Biology seems to be swept away, as by an ocean tide, into 

 the sea of a vast speculative inquiry. Evolution is a 

 word to conjure with, and the part played in this by 

 Natural Selection, by Sexual Selection etc., the significance 

 or insignificance of acquired characteristics, whether or 

 no these can stamp the whole organism as with a die, so 

 that by heredity they are transmitted to a descendant, 

 such problems offer so fascinating and so extensive a field 

 for Biological speculation, that one side of Biological 

 inquiry, that, namely, which determines the structural 

 changes in consequence of growth either of the individual 

 or of the race, has become of late years predominant. 

 And yet such problems have been attacked almost entirely 

 from one aspect and no systematic attempt has been made 

 upon the functional side of the question. — Would it not 

 therefore be wise if Biologists planned physiological 

 investigations which should, in the end, throw light on 

 the transmission or inheritance of functions as well as of 

 structures ; but for this inquiry previous knowledge of the 

 functions is indispensible. In what respects do the func- 

 tions of the tissues of animals resemble or differ from one 



