TAXONOMY, LIFE-HISTORY, AND GENERAL 5 



by any female in a given season do not immediately pass into the 

 oviducts to fertilize the eggs, but pass into the receptaculum seminis 

 and remain there through the winter to fulfil their ultimate purpose 

 In the following May or June. Thus the segmenting eggs which 

 Rusconi found to be present in the oviducts at the time the sexes were 

 pairing were those fertilized by the sperms received during the 

 amplexus of the previous year. 



An excellent account of the pairing is given by van Leeuwen 

 (1907), who observed the act in his vivarium. He states that it may 

 occur at any time from June to September (or even in October if the 

 weather is warm) and he only saw it occurring in the evening, and on 

 land. Van Leeuwen describes the male pushing his nose under the 

 hind-legs of the female and working his body forwards until his head 

 is directly under hers. He then embraces the fore-limbs of the female 

 with his own fore-limbs and, with a quiver of the body, deposits a 

 spermatophore on the moss. The male then rotates the posterior 

 part of his body through 90° but still retains his hold of the female, 

 who then lowers her cloaca on to the spermatophore and receives 

 it therein. The spermatophores are described by the same author 

 as transparent yellowish pyramids of gelatinous consistency, about 

 8-10 mm. high by 4-6 mm. broad, and are deposited with the 

 sharply pointed apex directed vertically upwards. 



Kammerer (i 907) agrees with van Leeuwen, but has also seen the 

 male approximate his cloaca to that of the female and pass the sper- 

 matophore directly into it. He also claims to have seen copulation 

 occur in water as well as on land, and says that then no such approxi- 

 mation of the cloacae occurs. His observation remains unsupported 

 by any other observer. 



The segmentation of the o.^^ and the early development were 

 first studied by Kupffer (1879), Benecke (1880), and Gronroos 

 (i 895 and 1898), the work of the last-named being the most detailed. 

 In spite of the large amount of yolk present, segmentation is holo- 

 blastic but is unequal. 



To summarize the essential facts that have been thus laboriously 

 unravelled we may say that the larvae are born in early spring from 

 April to May or June, while they have been observed as early as the 

 1 6th of January (Paratre, 1 894), the exact period depending on local 

 conditions. Ovulation then occurs, and the eggs thus released are 

 fertilized high up in the oviduct by sperms which have wintered in 

 the receptaculum seminis of the female. Shortly afterwards, during 

 July to September, pairing takes place, and the sperms then received 

 enter the receptaculum seminis and are stored for use in the following 



