THE ANIMAL PARASITES 649 
(bulbul), to be associated with subserous cysts of the 
intestine (weaver) and with profound anemia (liothrix). 
The birds affected are mostly small, inexpensive ones, but 
the inf estment is important because of its frequency and 
deserves study of the means of transmission. 
Physaloptera in Opossums and Badgers. — These 
worms were frequent findings for a period of years and 
were particularly impressive on account of the large 
number of parasites present. The stomach often con- 
tained scores, more or less securely attached to the 
mucosa by the head. The worms average an inch or two 
in length and perhaps an eighth of an inch in thickness. 
P. turgida is the only species we have identified (three 
examinations). As to pathogenicity we have not observed 
that definitely constant lesions are induced by the para- 
sites. In several instances the gastric mucosa has shown 
the mosaic appearance indicative of chronic gastritis, a 
condition not necessarily incited by, but certainly aggra- 
vated by, these worms ; at least significant is the habit of 
the worm to imbed its head in the gastric mucosa. In one 
instance the microscope has revealed a most severe 
fibrosis of the submucosa. The fibrosis was not so much 
diffuse as it was local or nodular, and in favorable places 
the ova of physaloptera could be discovered in the centres 
of the nodules, and thus betrayed the previous presence 
of the adult worm there. In this individual animal the 
case against the physaloptera is clinched by direct evi- 
dence. In other cases we have circumstantial evidence. 
Whereas it is not a deeply burrowing parasite, it is still a 
penetrative one, and this is sufficient to compromise the 
all important ' ' integrity of the mucosa. ' ' It should there- 
fore be considered pathogenic in all cases, because open 
to suspicion in several directions — abstraction of tissue 
juices, irritation by its products or movements and by 
opening up an avenue for bacterial infection. 
Tropidocerca in Birds. — This is a blood-red nematode 
of the size of a mustard seed to that of a peppercorn which 
42 
