CHAP. xr. 



Of the Expanfion^ Groivth^ and Delivery of the 

 Foetus^ <i}'c. 



IN the expanfion of the foetus, two different 

 fpecies of growth are dillinguifhable : The 

 firft, which immediately fucceeds the formation 

 of the foetus, is not uniform in all the parts of 

 the animal. The nearer the foetus approaches 

 to maturity, the growth of the parts is more 

 proportional j and it is not till after the birth, 

 that all the parts grow nearly in an equable 

 manner. We muft not imagine, that the foe- 

 tus, at the time of its formation, has the exa£t 

 figure of an adult. The fmall embryo, it is 

 true, contains all the parts elTential to a man ; 

 but they differ in their fucceffive expanfion. 



In an organized body, like that of an animal, 

 fome parts may be luppofed to be more effential 

 than others ; and though none of them are ufe- 

 lefs or fuperfluous, yet there are fome to which 

 others feem to owe their growth and difpofition. 

 Some parts may be confidercd as fundamental, 

 without which the animal could not cxift, and 

 others as only fuperficial and acceffory. The 



latter 



