DEVELOPMENT OF PEEIPATUS NOViE-ZEALANDI^. 231 



figured iu figs. 25 and 26 to those which were just ready to be 

 hatched. 



The second supply arrived in November^ but most of the 

 creatures were not opened till December. One female, which 

 was opened on November 27ih, contained several fully deve- 

 loped embryos, while iu one opened on November 30th the 

 uterus was empty. Seven females which were opened iu the 

 middle of December contained only unsegmented and seg- 

 menting ova in their uteri. 



In the last supply, which arrived last April, there were nine 

 females, which were opened on the 18th day of the month. 

 Of these five had no embryos in the uteri, one had several old 

 embryos, one segmenting ovum, and two embryos, one of 

 which is shown in sections in fig. 15; another contained 

 several old embryos, one segmenting ovum (which is shown 

 in section in fig. 11), and two of the stage represented in fig. 

 17; another contained the embryos, sections of which are 

 shown in figs. 13, 18, 19, and 20, and also one unsegmented 

 and several segmenting. 



The New Zealand species, like all the others which are so 

 far known, is viviparous, the embryos undergoing the whole 

 course of their development in the uterus of the mother. 



The ripe ovum is very large as compared with those of 

 Peripatus capensis and P. Edwardsii, measuring about 

 1-5 mm. in its long axis. This large size is due to the enormous 

 amount of food-yolk with which the egg is charged. 



The egg is enclosed iu a thick tough shell, which in the 

 fresh state adheres closely to it ; after treatment with certain 

 reagents it becomes somewhat distended, and can be pricked 

 or removed. This is especially the case with eggs which are 

 preserved in hot corrosive sublimate, which causes the shell to 

 swell up, to become less tough and to lie at a greater distance 

 from the egg, so that it can be quite easily removed without 

 damaging the surface of the egg. This is not so easily accom- 

 plished in cases where the corrosive sublimate was not heated, 

 and the surface of several of my eggs was more or less injured 

 in the process of removing the shell. It is necessary to prick 



