LOXOSOMA. 3Cv> 



This observation shows that the zoosperms are destined to fertilise 

 the ova in other individuals, and not in the polypide in which they 

 originate. This fact, however, is not conclusive against herma- 

 phroditism, and the separation of the sexes must be established by 

 the study of the female. 



The female. — In young individuals and in buds still attached, 

 some granular cells, hardly distinguishable from those of the 

 hypoderm {v, Pl.XXII, fig. 2), are visible in the space occupied at 

 a later period by the testicles or the eggs. In the males two of 

 these cells, placed one on each side, increase greatly in size and are 

 developed into the testicles. In the female there are many on each 

 side containing oil-globules of a yellow colour, and in some respects 

 not unlike the hepatic cells. INuclei were not observed in them, 

 but might readily escape detection ; nor was it possible to decide 

 positively whether or not they were enclosed in a very delicate 

 sac. Certain it is, however, that the ova {w), relatively of large 

 size, are soon distinguishable, occupying the same position as the 

 testicles. At first a single &^^, only is visible on each side, placed 

 close to the wall of the stomach, round or slightly oval, enclosed 

 in a delicate vitellary membrane and an exceedingly transparent 

 ovisac, and showing in the centre of its granular vitellus a large 

 transparent germinal vesicle with a circular nucleolus. The egg 

 increases rapidly in size, and the vitellus, nearly transparent at 

 first, becomes more and more opaque from the multiplication of 

 the granules. Viewed by reflected light, the ovmn appears of a 

 chalk-white colour. Behind the first egg a second is soon deve- 

 loped, whilst the former, as it increases, is separated from the 

 latter, and moves towards the dorsal side within the vestibule. 



The eggs multiply without intermission, the older being pushed 

 forward in the vestibule, where they accumulate in increasing 

 numbers until it is entirely tilled by them. At this stage it is 

 evident that they are enclosed in a very thin-walled ovary, which 

 takes the form of clustered ovisacs. 



The vestibule, then, and especially the dorsal portion of it, is 

 in the female a true brood-chamber, in which the ova enclosed 

 in their ovisacs pass through the various stages of develop- 

 ment, finally leaving it, on the rupture of the sacs, as ciliated 

 larvae. 



It is a curious fact that the ova are developed alternately on 

 each side of the body — first an e^g on one side, then on the 

 other, and so on to the end. 



The Author has never seen, amongst the hundreds of polypides 

 examined, any trace of testicles or seminal vesicle in individuals 

 carrying ova, nor has he ever found an ovum in those which were 

 furnished with the male organs. The Loxosoma phascolosomatum 

 is, therefore, dioecious ; and in this respect, if Schmidt's observa- 



