THE ANIMAL KINGDOM. 



333 



In respect to their migrations the crustaceans have been 

 little studied ; we only know that some animals of this class, 

 of strange habits, perform some very singular journeys ; 

 these are the large crabs called land-crabs. Formed like 

 their congeners to respire water by means of branchiae or 

 gills, they yet live on land, and are met with in compact 



154. Corn-Weevil. 1. Grain of wheat, showing the punctured hole; and 5, the exit of the 

 perfect Weevil. 2, Pupa (natural size); 3, magnified. 4, Grain of Indian Corn, with Weevil 

 inside. 6 and 7, Corn-Weevil (Calandra gramma), natural size and magnified. 8 and 9, Rice- 

 Weevil (C. oryza), natural size and magnified. 



bands on the mountains and in the forests of Brazil, where 

 they dwell in holes. But each year these animals make a 

 pilgrimage to the sea in order to deposit their young there, 

 and this act performed they return to their favorite haunts. 

 As it is necessary during this long and double journey to 

 breathe either water, or at least moist air, nature has pro- 

 vided for every emergency. The tourlourous for these 

 crabs are popularly known by that name possess for this 

 purpose, above the branchiae, a kind of sacks which serve as 

 reservoirs of liquid. When one of these crustaceans wants 

 to travel, its first step is to take in a stock of water by com- 

 pletely filling these sacks. During its march the liquid falls 

 drop by drop upon the respiratory organs, and moistens the 

 vessels. The branchiae being thus constantly wetted, the 



