No. 3.] SPERMATOPHORES. 



403 



In those species of the Calanidae which have one or a pair of 

 7-cceptacula seminis, the phenomena are the same, except that the 

 spermatophores are attached to the pores of these receptacles, 

 and their contents pass into the receptacles, instead of directly 

 into the vulva. The spermatozoa find their way into the vulva 

 through connecting ducts, when the eggs appear. 



In the Calanidae, the male catches the spermatophore, as it 

 is extruded, with his fifth pair of limbs, and then places it on 

 the body of the female. The secretion which begins at once to 

 escape from the neck of the capsule serves to fix the latter first 

 to the limb and then to the genital pore of the female [p. 424]. 



In other families, the male and female lie with their ventral 

 surfaces together; the male seizes with his antennae the last 

 pair of swimming-legs of the female, then bends his abdomen 

 forward, and fixes the spermatophore directly on the opening of 

 the receptaciihtm seminis by means of a special secretion [pp. 



424-25]- 



c. Gammarus. — Delia Valle ^ states that the oviducts end 

 blindly, and that what should be the opening at the base of the 

 fifth pair of legs is completely closed, except at the moment of 

 oviposition. 



Copulation occurs while the female is still bearing young in 

 her pouch. The young leave the pouch ; and the female moults, 

 the male assisting in the operation. The ventral surfaces are 

 together, so that the papillae of the male are in apposition with 

 the region of the oviducal extremities of the female. As soon 

 as the moulting is finished, ejaculation of spermatozoa occurs : 

 the ova appear half an hour later. The spermatozoa are not 

 inclosed in sperm-cases, but they adhere to the ventral surface 

 of the fifth segment and on the plates of the pouch. The ovi- 

 ducts are forced open by pressure from within, and the ova are 

 covered with a viscid gelatinous mass which binds them and the 

 spermatozoa together. For this abstract I am indebted to Dr. 

 McMurrich. 



C. SPENCE BATE. Report on the Present State of our Knowledge of the Crus- 

 tacea. Report British Assoc, f. Adv. of Sc. 1880. pp. 230-32. 



d. AsTACUS. — " Copulation of the crayfish takes place, according to 

 the observations of M. Chantran,^ during a period which includes the 



1 Atti. Soc. Xat. Modena (3), YlII, 1S89. 



2 Comptes Rendus, July 4, 1870, LXXI, pp. 42-45; Ann. Nat. Hist., 4th Ser., 

 Vol. VI, p. 265. 



