AND THE LOWER ANIMALS. 47 



Epigenesis is really the starting-point of every organ 

 in the body. We have shown this elsewhere,* and 

 the details we have already given prove it to be 

 unquestionable. Science armed with the optical in- 

 struments of the present day, asserts most positively 

 that the blastoderm does not exist until formed from 

 the elements of the germ. Thus, we see that even the 

 first trace of the future being is a purely epigenetic 

 formation, and we can say the same of all the 

 organs in the body. All multiplication, according 

 to Schwann's doctrine, is nothing but epigenesis; 

 and this mode of formation is still more evident in 

 those cases for which the cell theory makes no pro- 

 vision. An organ first appears in the blastema, and 

 is developed at the expense of the latter, just as the 

 primary membrane itself is organized at the expense 

 of the altered yolk. 



The germinal area is the first seat of these epi- 

 genetic formations, as each of its leaflets gives rise 

 to a special series of apparatus, which are at first 

 very simple, and made up of elementary materials. 

 These, however, are afterwards completed, and 

 develop adjacent and accessory organs. The ali- 

 mentary canal, for example, has, when first formed, 

 none of the glands attached to it, whose juices will 

 afterwards be required in digestion. Soon, however, 

 a little cul-de-sac, developing a blastema, makes its 

 appearance at a certain point, and quickly exhibits 

 a cavity with indistinct walls, which, though simple 

 at first, gradually divide into branches. We perceive 



* The general questions relative to the doctrines of Evolution, 

 Epigenesis, and Accolement, are discussed at length in the " Sou- 

 venirs d'un Naturaliste." 



