80 HEREDITY AND ENVIRONMENT 



parts of the adult were present in the germ in 

 a minute and transparent condition as the 

 leaves and stem are present in a bud, or as the 

 shoot and root of the little plant are present 

 in the seed.^ In the ease of animals it was 

 generally impossible to see the parts of the 

 future animal in the germ, but this was sup- 

 posed to be due to the smaller size of the parts 

 and to their greater transparency, and with 

 poor microscopes and good imagination some 

 observers thought they could see the little ani- 

 mals in the egg or sperm, and even the little 

 man, or "homunculus," was described and 

 figured as folded up in one or the other of the 

 sex cells. 



This doctrine of preformation was not only 

 an attempt to solve the mystery of develop- 

 ment, but it was also an attempt to avoid the 

 theological difficulties supposed to be involved 

 in the view that individuals are produced by a 

 process of gradual development rather than 



^The little plant in the seed is itself the product of the de- 

 velopment of a single cell, the ovule, in which no trace of a 

 plant is present, but of course this fact was not known until 

 after careful microscopical studies had been made of the 

 earliest stages of development. 



