336 DR. A. E, SHIPLEY ON [ Mar. 16, 
T. nodularis* Rud. is found in the mucous and muscular coats 
of the stomach and duodenum of many species of Anatide. It. 
has frequently been observed in the domestic goose and is especially 
fatal to the young of this bird. 
T. tenuis Eberth ft occurs in the cecum of the grey goose, 
Anser cinereus Meyer, and of the domestic goose. Neumann 
states that it is “‘ rare.” 
Finally, we have the species S. quadriradiatus recently described 
by E. C. Stevenson. It occurred in considerable numbers in the 
intestines of a flock of fancy pigeons which had been almost 
destroyed by a malady of unknown origin early in 1904. In his 
article upon this epizootic, Stevenson points out that the presence 
of a few nematodes in the cecum of the pigeon causes little harm. 
If, however, the thread-worms exist in large numbers, disease 
becomes manifest. This Stevenson attributes to two causes: the 
first is the loss of blood ; but there is, I think, little or no evidence 
that these nematodes live on blood. The second cause is the 
piercing of the walls of the intestine t, which permit the bacteria 
of the contents of the alimentary canal to make their way into the 
peritoneal cavity, where they set up peritonitis. Evidence is 
gradually accumulating as to the occurrence of this, and some of 
the French authorities even think that such a perforation, made 
as a rule by 7richocephalus dispar, is one of the more common, if 
not the most common, causes of appendicitisin man. The presence 
of these worms further sets up an inflamed, catarrhal condition 
of the walls of the intestine, which leads toa debilitating diarrhea 
and to general disorders of the digestive system. As in other 
cases, the Nematodes doubtless give off toxins, the effect of which is: 
largely confined to the nervous system and to the cells in the 
blood of the host. 
SrRUCTURE. 
The genus Trichostrongylus has recently been established by 
Looss § to include certain forms which he has separated out from 
the large genus Strongylus. The Strongylus pergracilis of Cobbold 
corresponds so closely in structure with the species described by 
Looss that I think there can be no doubt that it also should be 
included in the new genus. The suggestion made above that 
Strongylus tenuis Eberth of the goose should also be reckoned 
as a species of Z'richostrongylus was made to me by Mr. R. T. 
Leiper. 
Specimens of 7’. pergracilis are found in the cxca of grouse. 
They are apt to cover themselves with mucus and dirt, and are 
* Wedl, SB. Akad. Wien, xix. p. 46, and Schneider, Monogr. d. Nematoden, 
p. 148. Nan 
+ Wiirzburger nat. Zeitung, ii. p. 47. Von Linstow, Troeschel’s Archiv, 1. 1876, 
5 Gb 
{ An actual perforation of the membrane is not in all cases necessary. There are 
examples of bacteria traversing the wall or parts of the wall of the alimentary canal 
which have been locally or temporarily weakened in some way. 
§ Centrbl. Bakter. Parasitenk. xxxix. 1905, p. 409. 
