192 THE LIFE OF CRUSTACEA 



was seen it might be taken as an indication that 

 fresh water was not far off. It lives in deep holes in 

 the mud at the sides and bottom of the brooks." 

 Dr. Andrews tells me that he never saw this species 

 at or near the sea (in marked contrast to Gecar- 

 coidea), and this agrees with the observations of 

 other travellers on species of the genus Cardisoma, so 

 that the breeding habits remain unknown. There is 

 every probability, however, that in this case, also, the 

 young stages are passed in the sea. 



The student will find, in many textbooks on 

 zoology, the statement that some Land Crabs of the 

 genus Gecarcinus develop without metamorphosis. 

 Although it is impossible, with our present know- 

 ledge, to state definitely that this is not the case, 

 there is absolutely no evidence to support it, and it 

 is an interesting example of the way in which 

 erroneous statements sometimes gain currency in 

 science.^ It is based upon the fact that in 1835 

 Professor J. O. Westw^ood described the early stages 

 of " a West Indian Land Crab," in a paper " On the 

 Supposed Existence of Metamorphosis in the Crus- 

 tacea," published in the Transactions of the Royal 

 Society. Professor Westwood found that the em- 

 bryos extracted from the egg possessed all the 

 appendages of the adult except the swimmerets, and 

 that young specimens clinging to the abdomen of 



^ I am indebted to Mr. J. T. Cunningham for calling my 

 attention to some of the facts here recorded. 



