DEGENERA TION. 



25 



At first it has but three pair of hmbs, but it soon 

 acquires additional pairs, and a jointed body, and 

 thus by gradually adding to its complexity of struc- 

 ture as seen in Figs. 5 and 6, it approximates more 

 and more to the adult form from the ^^^ of which 

 it originated. 



-^~ 



Fig. 5. — Larva of the Shrimp Peneus. 



Fig. 6. — More advanced larva of 

 the Shrimp Pcncus. 



And now we are approaching the main point to 

 which I wish to draw the reader's attention. In at- 

 tempting to reconstruct the pedigree of the animal 

 kingdom and so to exhibit correctly the genetic 



