IIG REPORT— 18u 4. 



bryos, sonic few empty shells, and several highly active embryos adhering- 

 by their finely pointed tails to the glass slide on which the mud was spread 

 out. The whole aspect and behaviour of these embryo nematodes differed 

 very markedly fi'om those of Ascaris osculata, and also from the young 

 Anguillulce. The digestive organs were well developed in several ; but at 

 least one specimen was dead and disintegrated internally. I could not 

 satisfy myself as to the existence of any rudiments of a reproductive 

 apparatus. 



On the 18th of July, 1863, I also placed some of the above advanced eggs 

 in muddy pond-water, to which I added some cowdung. This was also 

 examined on the 23rd September, when a few empty shells were seen, their 

 former occupants not being visible. Most of the eggs contained segmented 

 yelks and young embryos. On the 2oth of April, 1864, the same conditions 

 were still observed : none of the embiyos had escaped. At the above-men- 

 tioned date (July 18), ova were also put into another jar of pond-water, 

 ■with horse-dung added. In this case (September 23) a few living embryos 

 were detected, free and active. On the 25th of April, 18G4, I found the 

 eggs still segmenting, a few with embryos ; but none of the latter were 

 observed free. At the same period (July 18) other eggs were deposited in 

 simple horse-dung ; and here also (September 23) a few embryos had freed 

 themselves of their egg-covering, and were still living. On the 25th April, 

 1864, I found numerous embryos free, active, and much grown. 



On the 23rd December, 1863, I still found the majority of the eggs in 

 the fresh water (of April 24th), with theu* embryos coiled in the interior 

 and aUve. One free embryo was particulaiiy active, and there were several 

 empty shells. On the 25th April, 1864, they still seemed to have under- 

 gone no material change, and I did not on this occasion observe any free 

 embryos. 



As the free embryos of A. megalocephcda, reared in horse-dung, had, on 

 the 4th of January, 1864, attained considerable size, and likewise exhibited 

 traces of the sexual organs, I washed them out of the excreta ; and, after 

 straining through muslin, they were placed in a large jar with the water 

 employed in separating them. My next object was to administer part of 

 them to a horse, with the view of rearing the sexually matiu-e woim. This 

 was done on the 26th of April, 1864 ; but here again I was prevented 

 ascertaining the result. The horse, becoming violent and vicious (from other 

 causes), was slaughtered on the seventh day after the worm-feeding ; and, 

 by another mischance, I was also prevented from examining the intestines. 



When I last examined the ova first placed in fresh water on the 24th of 

 April, 1863, many of them still displayed living embryos in their interior, 

 whilst hundreds of embiyos were found free ; the latter, however, showed 

 no further advance in growth, and were by no means so active and healthy- 

 looking as those contained in the jar of impure water. I satisfied myself, 

 moreover, that these last were a trijfie more advanced in development. 



10. Oxyuris vermicularis.— On the 22nd December, 1862, numerous eggs 

 were deposited in the substance of the pulp of two partially rotten pears 

 and one decayed apple. I had not noticed embryos in cmy of the eggs at 

 the time of their lodgment within the parent oviducts ; but, on examining 

 the fruits ten days later (January 1st, 1863), I found many of the ova to 

 contain the characteristic tadpole-hke embryos of Oxyuris. On the 13th of 

 March following, none of the embryos appeared to have escaped their shells ; 

 but when I again examined these pears and the apple, on the 17th and 18th 

 of the succeechng July, I found multitudes of minute nematodes which, at 



