xii INTRODUCTION 



economy of material and partly in the belief that this aids under- 

 standing of the topographical and other interrelations between the 

 systefks, encouraging the building up of a conception of the indi- 

 vidual organism as an integrated unit. 



The general matter of Part I is purely accessory and, though 

 necessarily incomplete in many ways, is designed to afiford a com- 

 prehensive view of the various factors upon which mammalian 

 structure depends. It will be found that only the first few chapters 

 are introductory in most respects, the remainder being rather ex- 

 planatory and hence most valuable if used to supplement the direc- 

 tions for dissection as this is carried out. 



Regional sections of the foetus as figured in Part i, or frozen 

 sections of the adult animal, are a useful adjunct, since they can 

 be used either for points of general organization, or, being sub- 

 stantially correct for two dimensions, for the removal of erroneous 

 impressions of the position of organs incidental to their displacement 

 in dissection. 



