| OCR Text |
Show 128 DR. T. S. COBBOLD ON N E W OR RARE ENTOZOA. [Feb. 3, very well with Bremser's figure of the same part. The arcuate spicules, however, are not so sharp at their tips as his illustration implies, and they are certainly more uniform in thickness. Dujardin remarks that Rudolphi has represented the spicules as being straight, whereas he himself always found them curved. Rudolphi, however, was scarcely in error, since I have repeatedly noticed that these arcuate organs are very nearly straight in their perfectly retracted condition. Like Dujardin (and without having previously consulted his description), I was particularly struck with the appearances presented by certain large perivisceral corpuscles, the presence of which originally suggested the specific name of the worm. Dujardin very appropriately calls them corpuscules orbiculaires diaphanes, but compares them, somewhat unfortunately, to little acephalocysts. These bodies, as he says, are many times larger than the ova. For my own part, I believe they are nutritive in character, and, like the fluid in which they float, are, I suspect, chemically comparable to the juice of flesh. At all events, Dr. Marcet has proved that the perivisceral fluid of the large lumbricoid worm of the horse (Ascaris meyalocephala) partakes of this character; and it is no uncommon thing to notice similar corpuscles in the bodies of other nematode worms. Dujardin himself refers to similar bodies in an Ascaris from the Perroquet. I have purposely represented a few of the eggs along with the nutritive corpuscles, side by side, in order to show their relative sizes (fig. 10). Notwithstanding the facts thus set forth in connexion with the parasitic epidemic affecting the Antwerp Smerles, the entozoa in question do not appear to be very common. Dujardin has remarked that Heister, at Rostok, and Gebauer, at Breslau, found this parasite abundant at the beginning of the 18th century; but, according to examinations conducted at Vienna, the worm was found in the Common Pigeon in only 11 instances out of 245, and thrice only in 38 examples of the Ring-Dove; moreover the examination of 87 other pigeons and doves of different species yielded entirely negative results. These data are of high practical interest, and they serve to throw light upon questions of epidemiology. I may add that the Dublin helminthologist, Bellingham, long ago noticed the occurrence of this parasite in Ireland. EXPLANATION OF PLATE XVIII. Fig. 1. Filariagracilis: male, nat. size. 2. The same: head and neck, enlarged 40 diam. 3. The same: tail, mag. 70 diam. 4. The same: spermatozoa, mag. 350 diam. 5. Spiroptera turgida: nat. size. 6. Ascaris cuspidata: tail, enlarged. 7. Ascaris maculosa: egg, mag. 330 diam. 8. The same: head of female, mag. 20 diam. 9. The same: tail of male, mag. 35 diam. 10. The same: eggs and nutritive corpuscles, enlarged. |
