EUPAGTTRT7S. 547 



intracellular duct leads. The glands, which are 

 profusely scattered on the under-surface of the abdomen 

 in the dermis, secrete a mucous fluid which has been 

 assumed to be the medium by which the eggs are attached 

 to the pleopods. The exact method of attachment is still 

 unknown, and nearly every observer of the egg-laying 

 has a different theory of fixation. Huxley in his 

 "Crayfish" considers that the eggs are coated with a 

 viscid matter as they leave the oviducts* and Lereboullet, 

 who has observed the process closely, is of the same 

 opinion. The latter observer states that the cement 

 glands are for the purpose of filling the " brood 

 chamber" with mucus in which the eggs and sperms 

 mix, and it is highly probable they have the same 

 function in the Hermit Crab. 



DEVELOPMENT (PI. VI). 



It is not known how fertilisation is effected in the 

 present species. Copulatory organs are altogether 

 absent, and neither the transference of the sperms nor 

 the act of oviposition has ever been observed. Mayer 

 (see below) argues from the apparent impenetrability of 

 the outer coat of the egg when it leaves the oviduct that 

 fertilisation must be internal. He is unable to offer any 

 explanation of the method by which the free sperms gain 

 access to the ovary. There seems no good reason why the 

 egg coat should be considered to be more impervious to 

 the sperms in Eupagurus than in the Lobster or Crayfish. 

 In both of these animals fertilisation is undoubtedly 

 external, and in the case of the Crayfish every step in the 

 process has been observed. It is not possible for the 

 Hermit Crab to form a brood pouch by flexing its 



* Bumpus (loc. cit.) comes to the same conclusion with regard 

 to the American Lobster. 



