ON THE DEVELOPMENT AND MIGRATIONS OF THE ENTOZOA. 119 



that a largo number of the eggs had escaped (probably by the bursting of the 

 worms), some of which contained the characteristic tadpole-like embryos. I 

 could not, however, find one single embryo, although there were hundreds 

 of empty eggs and broken-up egg-shells. One embryo presented an appear- 

 ance of central division — the only instance I had seen up to the date in 

 question. 



From a subsequent and final examination, it was clear that the yelk and 

 embryonic contents of all the ova had disiategrated, sometimes causing the 

 shell to burst. 



On the 2nd of January, 1863, I fed a monkey (Maeacus) with numerous 

 eggs of Oxyuris, containing living embrj'os. On the 11th of Pcbruary this 

 animal was destroyed ; but there were no young Oxyuiides discoverable in its 

 intestinal canal. At one time 1 almost looked for a positive result, as the 

 monkey displayed marked signs of anal iiTitation after the worm-feeding. 



On the 10th and on the 14th of January, 1863, fresh eggs of Oxyuns, in 

 which the characteristic embryos were well developed, were admiaistered 

 to a large goat. This animal was destroyed on the 21st of January, without 

 furnishing any other than a negative result. 



11. Strowjylus armatus. — On the 9th of March, 1863, I placed a quantity 

 of the eggs of this species in a jar of fresh water, ■without any vegetable 

 matter. On examining the contents of the jar, on the 16th of the folio wing- 

 July, I could find no embryos, ova, or entire egg-shells ; but there was a 

 quantity of granular debris at the bottom of the vessel. 



12. Prosthecosacter injlexus. — Through the kindness of 3Ir. Kiel, I received, 

 on the 19th of October, 1863, the lujags of a porpoise which had just died 

 at the Zoological Society, Eegent's Park. The hmgs were quite fresh, and 

 plugged throughout by the presence of multitudes of this parasite. After 

 examining the ova very carefully, I placed a quantity of them, afready con- 

 taining incompletely developed embryos, in salt water ; and I also mixed 

 some of the bronchial mucus of the porpoise (which, besides eggs, contained 

 several free embryos) with salt water in a separate vessel. 



On the 23rd December, 1883, I carefuUy examined the contents of both 

 jars. In the jar originally containing eggs only, I found one egg with an 

 embryo stiU coiled within it, many of the other eggs having apparently dis- 

 appeared, leaving a very small quantity of debris, partly consisting of sheU- 

 fragments. Two living embryos were detected, severally measuring about 

 yij" and -Jy". They displayed a tolerably complete digestive apparatus ; 

 but there were no certain traces of sexual organs. There were a few speci- 

 mens of Euplotes traveUing about. 



The jar containing eggs and yoxmg displayed, at the same date of exami- 

 nation, several active embryos in all respects resembling those above men- 

 tioned, and also an astonishing number of animalcules (Euplotes). But 

 there were also several larval nematodes of much larger size, and yet possi- 

 bly belonging to the same species. There were, it is tme, some slight 

 diiferences, possibly due to their more advanced growth. They measured 

 about Jy". 



On 25th April, 1864, I found both jars to contain living embryos, those 

 mixed with frothy mucus from the bronchi being more niuuerous and much 

 more largely developed. The longest specimen, developed from the ova, 

 measured no more than ■^" in length. 



"When I last examined the contents of these jars (July 21, 1864), both 

 still contained living worms, the larger specimens reared from the egg still 

 measuring only -^L of an inch. The largest embryo from the jar containing 



