SPH^EULARIA. 63 



extremity. As one might gather from the name, its body is every- 

 where covered by numerous small warts or button-like projections, 

 in all numbering about 800. These spherules are, for the most 

 part, transparent, and according to Lubbock, each projects from 

 iMo" ^0 i^" above the general smooth surface of the integu- 

 ment. There is neither mouth, oesophagus, intestine, nor 

 anus ; but in place of these there is a large fatty mass or corpus 

 adiposum containing numerous cells. This peculiar organ, according 

 to Lubbock, "is homologous, not with the whole intestinal canal 

 of Nematodes, but only with the intestine ; and we find, in fact, that 

 in Gordius the oesophagus is very short, and opens at once into 

 the anterior end of the corpus adiposum ; so that to pass from 

 this genus to Sphgerularia, it would be necessary to shorten the 

 oesophagus a httle more, and then the wall of the corpus adiposum 

 would be immediately attached to that of the body. So far, there- 

 fore, as concerns the corpus adiposum and the oesophagus, Sphse- 

 rularia agrees neither with Gordius nor Mermis, nor, indeed, with 

 one more than the other ; since, if it agrees with Mermis albicans 

 in the double series of large fat cells, it has no oesophagus, and in 

 this respect more nearly resembles Gordius." The reproductive 

 organs consist of a single ovary, uterus, and terminally situated 

 vulva. These organs in the full-grown females contain ova in 

 all stages of development up to the condition of advanced yolk seg- 

 mentation ; but it does not appear that embryonic formation takes 

 place whilst the eggs are still m utero. "The young animals 

 are born soon after the eggs are laid. They are about s," in 

 length, and ^' diameter at the broadest part." Before Mr. 

 Lubbock conducted his inquiries the male appears to have been 

 entirely overlooked ; but there need be no surprise at this, seeing 

 that there is a remarkable disparity between the sexes. The male 

 Sphaerularia is so extremely minute, that if it have ever been 

 seen by previous observers, it is more than probable they have 

 mistaken it for a young one. Mr. Lubbock calculates that " the 

 male is more than 28,000 times smaller than the female. It 



