38 
far, fed one batch of eggs to a prairie dog, first performing 
laparotomy to make sure it was not already infested; 
but the control rat failed to develop the disease. This 
indicates that the ova were not in the infestive stage even 
though they contained motile larvae. Further feedings 
will be made shortly. 
Trichina Spiralis in the Polar Bear. 
Encysted forms of this worm were found in almost 
unbelievable numbers in the above animal at autopsy. 
Since rats are possible, and in some localities, common, 
transmitters of the disease, we examined fifty which were 
caught in different parts of the garden but in no case with 
parasitic findings. This shows that the bear probably 
brought the disease with him from the arctics and cer- 
tainly that our wild rats are not transmitting the disease 
to other carnivora. 
Trichinosis in Cold Blooded Animals. 
The recognition of trichinosis at the autopsy in the 
polar bear raised the question whether other animals 
in the garden might not also be affected. As rats and 
pigs are the common transmitters we thought of the 
snakes to which both these animals are fed. Although 
this was not thought likely, nevertheless' a King snake 
was fed on an experimentally infested trichina mouse. 
The reptile died spontaneously 102 days later, which 
is three times as long as is necessary for the parasites to 
develop. The muscles were examined thoroughly for 
trichinosis but none was found. They did contain 
filariae, adult and larval, and larvae were also found in the 
intestine, but resembling more those of a filaria than a 
trichina. The latter were fed and injected intraperi- 
toneally into white rats without reproducing the disease. 
After our experiment had started we found that Gujon 
has also been unsuccessful in infesting cold blooded 
animals, but that salamanders contracted the disease 
when kept at a temperature of 30°C. We conclude that 
there is no danger, then, even if we should feed trichinous 
