STRUCTURE AND FUNCTION 77 



of adaptation ruled the transformations of form. Geoffrey 

 considered that structure determined function, that changes 

 of structure, however they might arise, caused changes 

 of function. " Animals," he writes, " have no habits but 

 those that result from the structure of their organs ; if the 

 latter varies, there vary in the same manner all their springs 

 of action, all their faculties and all their actions." 1 



Again, "a vegetarian regime is imposed upon the Ouad- 

 rumana by their possession of a somewhat ample stomach, 

 and intestines of moderate length." 2 The hand of the bat 

 has become so modified as to constrain the bat to live in 

 the air. 3 



The best example of Geoffrey's insistence upon the 

 priority of structure to function, and so of his purely morpho- 

 logical attitude, is perhaps his interpretation, already alluded 

 to, of the appendages of Articulates. The segments .of the 

 Articulate are, he says, the equivalents of the bodies of the 

 vertebrae of higher forms. Now " from the circumstance that 

 the vertebra is external, it results that the ribs must be so too ; 

 and, as it is impossible that organs of such a size can remain 

 passive and absolutely functionless, these great arms, hanging 

 there continually at the disposition of the animal, are pressed 

 into the service of progression, and become its efficient 

 instruments." 4 The ribs become locomotory appendages. 



We may compare the similar thought that the ear ossicles 

 are simply opercular bones reduced and turned to other uses. 



Geoffroy could not but recognise the correlation of 

 structure to function, for this is a fact which imposes itself 

 upon every observer. He recognised also correlation between 

 functions, as when he pointed out the connection between 

 increased respiration and enhanced muscular activity in birds. 5 

 He interpreted structure at times in terms of function, the 

 short, strong clavicle of the mole as an adaptation to digging, 

 the keeled sternum of birds as an adaptation to flying, and so 

 on. But we may say .that his whole tendency was to disregard 

 function, to look upon it as subsidiary. He protests against 

 arguing from function and habits to structure, as an " abuse 



1 MammifereS) i., Le<;on 4, p. 17. 



2 Loc. cit., Le$on 5, p. 8. 3 Loc. cit,, Lecon 13, p. 6. 



4 Jsi's, p. 539, 1820 (2). 5 MammifereS) i., Legon 4, p. 6. 



