I/O 



THE QUARTERLY REVIEW OF BIOLOGY 



happening in the peripheral field of vision 

 than do Europeans. Their art objects too 

 are more crowded with detail than are the 

 corresponding productions of the white 

 races of mankind. It is true that Shell- 

 shear in his purely anatomical exposition 

 refrains for the moment from making any 

 functional comparison, but if some 

 difference of the kind indicated should 

 also be found by appropriate physiological 

 experiment to exist between Chinese and 

 Europeans, it is plain that we should 

 here have a means of observing and 

 tracing structural and functional flux 

 within the limits of one and the same 

 species. The numberless recorded obser- 

 vations of anatomical differences between 

 the different races of mankind have 

 also no doubt their functional counterpart, 

 though methods of experimental com- 

 parative treatment are as a rule less 

 immediately obvious than in the particular 

 case just cited. 



The odor-secreting glands of mammals. 

 In his article, "Mammalia," in the ninth 

 edition of the Encyclopaedia Britannica 

 Flower has collected together a list of 

 odor-secreting glands connected with the 

 skin of various mammals. His statement 

 is as follows: "To this group of struc- 

 tures belong the suborbital gland or 

 'crumen' of Antelopes and Deer, the 

 frontal gland of the Muntjak and of 

 Bats of the genus Hipposiderus, the sub- 

 mental gland of the Chevrotains and of 

 Tapbo^ous and some other Bats, the post- 

 auditory follicle of the Chamois, the 

 temporal gland of the Elephant, the 

 lateral glands of the Musk-Shrew, the 

 dorsal gland of the Peccary, the inguinal 

 glands of Antelopes, the preputial glands 

 of the Musk-Deer and Beaver (already 

 alluded to in connection with the use 

 made of their powerfully odorous secretion 

 in medicine and perfumery) and also of 

 the Swine and Hare, the anal glands of 



Carnivora, the perineal gland of the Civet 

 (also of commercial value), the caudal 

 glands of the Fox and Goat, the gland on 

 the humeral membrane of Bats of the 

 genus Saccopteryx, the post-digital gland 

 of the Rhinoceros, the interdigital glands 

 of the Sheep and many Ruminants, and 

 numerous others. In some of these cases 

 the glands are peculiar to, or more largely 

 developed in, the male; in others they are 

 found equally developed in both sexes." 

 In this striking series any question of 

 homology between the different glands is 

 excluded because of topographical reasons. 

 Yet the glands in question form a related 

 group, being derivatives presumably of 

 sebaceous glands and subserving somewhat 

 similar uses. At the same time each is 

 obviously an independent invention, and 

 the odors or chemical products elaborated 

 differ one from another. How should 

 one set to work to extract from such 

 a series further information respecting 

 phylogenetic flux? Clearly one must first 

 invoke physiology and biochemistry. 



The great trouble with morphology as 

 a guide in the elucidation of animal form, 

 or even as a means of approach to struc- 

 tural and evolutionary problems, is that 

 it is silent as to the mode of operation of 

 the structures with which it professes to 

 deal. Imagine a refined morphology of 

 the brain of mammals, based purely on com- 

 parative criteria gross and microscopic, 

 but which fails to envisage the experi- 

 mental results of the workers on cerebral 

 localisation, ranging from Fritsch and 

 Hitzig to Henry Head, or of the workers 

 on cerebral "educability," from Goltz to 

 Pavlov! The one thing that gives 

 life and meaning to the comparative 

 anatomical knowledge of the cerebrum 

 and saves it from being an arid collection 

 of maps and diagrams, is the physiological 

 work that has proceeded pari passu with 

 the anatomical. Indeed the time and ef- 



