198 



ASSOCIATION OF ORGANISMS THE WEB OF LIFE 



Fig. 1146. Sacculina. A, Shore-Crab (Carcinus mcenas], with the parasite projecting from the under side 

 of its tail. B-G, Stages in development, greatly enlarged; B, nauplius stage, with two pairs of feelers (i, 2) and 

 one pair of jaws (3); c, mussel-shrimp stage, showing modified first pair of feelers (f]\ D, the same, attached 

 by one feeler (/) to the base of a crab's bristle (br.}, the hinder part of body is being thrown off; E, F, G, latei 

 stages, showing formation of a tube (t] through which the soft substance of the parasite passes into the crab. 



