442 PARASITES OF .ANIMALS 



placed themselves within the pyloric opening, their bodies 

 partly lodging within the duodenum. The duodenum itself 

 was crowded with worms, their numbers somewhat decreasing 

 downwards. I removed thirty-six worms from the oesophagus, 

 proventriculus, and stomach, besides 166 others from the intes- 

 tinal canal, thus obtaining a total of no less than 202 nematodes 

 from this small host. Considering the large size of these 

 entozoa, the extent of infection must be pronounced remarkable. 

 The largest females measured 2J" in length. One of the most 

 interesting facts serving to exemplify a well-known habit of 

 lumbricoid worms generally consisted in the circumstance 

 that two of the parasites had succeeded in perforating the 

 horny lining membrane of the gizzard. The injuries had been 

 accomplished during the life of the host, for the walls of the 

 gizzard were inflamed opposite the perforations. There was a 

 little half digested food within the stomach, the debris of which, 

 when placed under the microscope, showed several ova. There 

 were no free embryos, neither had the development of the 

 freed eggs proceeded beyond yelk-segmentation. Free eggs 

 were also found both in the small and large intestine. The 

 eggs measured about g^" by 7o5 " in diameter. Referring to 

 my paper for further anatomical details, I can only add that, 

 despite these facts, the ascarides in question do not appear to be 

 a very frequent source of epizooty. It was remarked by Dujar- 

 din that Heister, at Rostok, and Gebauer, at Breslau, found this 

 parasite abundant at the beginning of the eighteenth century ; 

 but, according to examinations conducted at Vienna, the worm 

 was found in the common pigeon in only eleven instances out 

 of 245, and thrice only in thirty-eight examples of the ring- 

 dove ; moreover, the examination of eighty-seven other pigeons 

 and doves of different species yielded entirely negative results. 

 , The Dublin helminthologist, 



I Bellingham, noticed the occur- 



g|M4 VI / rence of this parasite in Ireland. 



V^ J^^r ^ n y a ^ em P* i so mu ch as to 



\ ^~" & '/ enumerate the species of nema- 



toids infesting birds would carry 

 me far beyond the aim and scope 

 ... ... of this treatise. One of the com- 



FIG. 74 Tail of the male Ascans vestculans. 



From a ring-necked pheasant. Original. monest Species IS AsCdTlS (Hete- 



' rakis) vesicularis. Many hundreds of forms have been described 

 by Dujardin, Diesing, Molin, Krabbe, and other systeinatists, 



