ON THE DEVELOPMENT AND MIGRATIONS OP THE ENTOZOA. 117 



the time, I referred to the ova and embryos in question. To add strength to 

 that conclusion, I noticed a number of empty egg-shells of Ox-}/iiris amongst 

 the loose and decayed vegetable parenchyma. These little nematodes mea- 

 sured about ^ of an inch in length, but their form did not correspond vnth 

 the shape of the Oxi/uris-emhrjo. The contents of one of the pears and the 

 aj^ple were subsequently employed in new experiments ; but the other pear, 

 which had now become thoroughly rotten and of a blackish-brown colour, 

 Avas retained for the purpose of preserving these j'oimg nematodes. On the 

 23rd of September, 1863, I again examined this pear, and found a consider- 

 able number of the nematodes which had scarcely advanced in length or 

 breadth. On the day following (24th) I had an opportunity of showing 

 them to Professor Leuckart, of Giessen, who considered it possible that they 

 might be the young of Oxyuris, notwithstanding their little resemblance to 

 the tadpole-like condition of the embryo as it exists in ova. He suggested 

 the jn'obability, however, of their being AnguUhilce, and was resolved to 

 satisfy his doubt on this score by repeating my experiment. It is known 

 that AnguilJuJa may suddenly make their aj^pearance in decaying vegetable 

 matter under similar conditions to those here recorded : but it seemed rather 

 singiilar that they should appear in such remarkable abundance in the three 

 specimens of fruit specially selected for my experiment. The fact that 

 empty egg-shells were found in the pear, associated with the equally im- 

 ])ortant fact that, before I introduced the eggs, I took the precaution to 

 examine the partially decayed pulp of these fruits, and ascertained that no 

 AncfuiUiilce or other nematodes existed in them, appeared at the time to 

 warrant the conelusion that the nematodes in question could only be refer- 

 able to Oxyiu-ls verniicuJaris. I have, however, since satisfied myself that 

 they were true Anguillules {A. pyri, T.S.C.)*. 



On the 18th July, 1863, a portion of decayed pear, containing the Anguil- 

 hiles, was placed in cowdung. This mass, though inclosed in a jar, became 

 very diy at the surface ; but on the 23rd September, when it was carefully 

 examined, several of the young nematodes were still alive, though very little 

 advanced in size. One, which appeared dead and rather smaller than the 

 others, still measured only the ^^ of an inch. 



At the same date (July 18) others were placed in the same material, with 

 water added, and here also I subseqiiently (September 23) found a few 

 inactive individuals. One appeared to be quite dead, its parenchyma having 

 degenerated into a mass of large fat-globules. 



At the same date (July 18), several Anguillules were placed, with portions 

 of the pear, in a small jar of pond-water. Niimbers of these were after- 

 wards found (Sept. 23) at the bottom of the vessel, stretched out and 

 exhibiting very few signs of vitality. They displayed traces of a phaiynx, 

 but the intestinal canal had not devekped. Their bodies only contained a 

 quantity of fine granules. 



At the same date (July 18) a considerable number of the Anguillules were 



* Having recently forwarded specimens to Mr. Henry Charlton Bastian, F.L.S., that 

 gentleman (who has specially and most successfully devoted his attention to the free 

 nematoids) has informed me (December 30th, 1864) that he recognizes two distinct spe- 

 cies from the pear. They belong to his genera ApheleucTms and Flectus respectively, 

 " two out of the foiu" genera whose members possess extraordinarj' tenacity of life." He 

 proposes to call the one AplielevcJms pyri, leaving the other at present imdescribed. The 

 portions of pear which I forwarded were perfectly dry and brittle ; and in confirmation of 

 my statements rcppccting tlic vitahty of the nematodes, Mr. Bastian remarks, in a letter 

 to me, as follows : — " Alter soaking I'or a few hours in water they resumed all their acti- 

 vity, as you had obseiTed."— Jan. 21st, 1865. 



