of a South- Sea Voyage. 265 



Of the several interestin*^ points arising- in the course of 

 the anatomical description the first occurs in the paragraphs 

 on the female generative organs. The ovarial wall is thin 

 and differs in structure from tliat of the oviduct, showing in 

 this point a resemblance to the Cape and Australasian species 

 and differing from the Neotropical. The eggs are follicular. 

 Immediately on leaving the ovary the oviduct is of a structure 

 different from that which it assumes during the rest of its 

 length, and this first portion of the oviduct is called by 

 Dr. Willey the " infundibulum," and likened to the funnel of 

 a nephridium. The ovary itself is compared with the end- 

 sac. Unfortunately there are no observations on the develop- 

 ment of these organs. 



The male generative organs, however, present features of 

 even greater interest than the female. The vasa deferentia 

 are symmetrical and pass to the exterior by a median ductus 

 ejaculatorius which is hardly larger than the vagina of the 

 female. This arrangement is precisely that supposed by 

 Moseley to have been the original condition of the parts in 

 question. The arrangement of the accessory glands is 

 different from that presented by either of the other sub- 

 genera^n fact, each section of the genus has these organs in 

 a condition quite different from that found in any of the 

 others. Dr. Willey suggests that they are capable of throwing 

 light on the Malpighian tubules of insects. 



But the crowning peculiarity of tlie New-Britain Peripatus 

 lies in the structure of its embryos. Of these a fairly complete 

 series Avas available for examination, owing to the fact that 

 each fertilized female contains a number of young of various 

 ages. Jn the following short account of their development it 

 will be best to use the author's own words where this is 

 possible. In the early stages " tiie embryonic area proper is 

 confined to a thickened tract at the posterior- ventral side of a 

 large oval vesicle. The rest of the wall of the vesicle is 

 composed of embryonic ectoderm and endoderm, which take 

 no immediate part in the formation of the embryo. Physio- 

 logically it corresponds exactly with the peripheral epiblast 

 and hypoblast of a mammalian blastodermic vesicle. As in 

 the latter, it is the ectoderm which is chiefly concerned in the 

 absorption of nutriment for the use of the embryo, as evidenced 

 by the vacuolar character of the cells." In a later stage the 

 vesicle comes to project behind as well as in front of the 

 embryo. 



By the appearance of a deepening transverse groove in the 

 embryonic area the embryo proper becomes U-shaped. In 

 the course of subsequent growth it becomes spirally coiled. 



