524 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



alimentary canal, in the dermal layer of the body wall, 

 and on the under side of the abdomen. Cuenot states 

 that the branchial glands give a mucoid secretion.* 



EXCRETORY SYSTEM (PL IV). 



The Renal excretory system of the Hermit Crabs 

 has attained a complexity which no other Crustacean 

 exhibits. In addition to the complex arborisations 

 which ramify between the viscera in the cephalo-thorax, 

 there is (in the present species) a large unpaired 

 abdominal sac. All this belongs to the antennary gland 

 (" green gland ") system. 



Excretion is also performed by separate cells in 

 various parts of the body — notably those in the gill axis, 

 and an excretory function has been attributed to the 

 "ferment" cells of the digestive gland. 



It is not possible to make a dissection of the 

 excretory system without previous treatment of the 

 animal. A spirit specimen rarely shows more than the 

 abdominal vesicle and the antennary gland, and, at best, 

 indistinct traces of the remainder of the system ; so it is 

 essential to make a complete study on living material by 

 means of injections. 



The substances which are suitable, par excellence, 

 for such injections are methyl-green and saurefuchsin in 

 solution in sea-water. A fairly strong solution, the 

 exact strength is immaterial, should be made of the 

 pure substance. One or two c.c. may be introduced into 

 the animal by means of a hypodermic syringe inserted in 

 the arthrodial membrane under the thoracic limbs. The 

 crab may now be returned to its shell and allowed- to live 

 for about forty-eight hours, after which it may be killed 



* Archives de Biologie. T- XIII., p. 250, 1895, 



