No. 629] HABITAT RESPONSES OF WATER-STEIDER 505 



considerable precision, to the moisture given off from the 

 sea. However, in other experiments with crabs she con- 

 sidered that the past life of the crustaceans and the char- 

 acter of the behavior, already acquired, must be taken into 

 consideration, in the interpretation of their present re- 

 sponses. Crabs, living in deep water, among rocks cov- 

 ered with algae and beaten by the waves, when placed on 

 the sand, in the vicinity of the sea, did not evince definite 

 hydro tropic movements, but, on the other hand, their re- 

 sponses were of a very different character. The factor, 

 in these responses, of importance to the present discus- 

 sion is that of sight. Vision, apparently, played a promi- 

 nent role in determining the direction of movement of the 

 crabs. Drzewina (1908, p. 1011) has given a rather full 

 statement concerning these facts : 



Les Carcinus de la zone basse de Fucus serratus, pris i\ une pointe 



converts d'algues et battus i)ni- flots. so comporteiit encore autre- 

 iiient: laches sur du sal)l('. :in v.ii>iiia-^v do la inor, an lieu de deseendre 

 vers celle-ci, ils se diriyftn iininraiaiciiiciii. en lipie droite, vers des 



on nienie dans le sens oppose u la nier. Et ceci, quelle que soit la direc- 

 tion du vent et du soleil. Ces memos Crabes, deposes sur du sable clair, 



