PLATE 101. Sacculina. 



A. Its nauplius larva. #. The Cypris stage in its development. C The adult Sacculina para- 

 sitic upon a crab, to the under side of whose abdomen it is attached, and whose body is pene- 

 trated in all directions by the root-like processes of the Sacculina. [From WEISMANN, after 

 DEL AGE.] D. A larva which has crawled into the interior of the body of a crab where it is 

 rapidly growing as it feeds from the blood of the crab ; it is now an almost shapeless mass of 

 cells. E. A section through a mature Sacculina. Most of its body has been pushed out from 

 the inside of the crab and now protrudes to the exterior. There are no appendages or sense 

 organs, and the nervous system (g) is greatly reduced. The body contains little but the ovaries 

 (pv.) and testes (/.) full of eggs and spermatozoa. [After DELAGE.j 



