254 Proceedings of Indiana Academy of Science 
calcareous skeletons with HCL, and then compressing them between two 
slides. 
Earthworms, from which most of the intestinal contents had been 
squeezed out, were placed into soil cultures containing larvae in differ- 
ent stages of development. These were examined at varying intervals, 
ranging from one to five weeks. The method of doing this was to 
place a cleaned individual into salt solution, in which it was cut open 
and the intestinal contents examined. Small pieces of the worm itself 
were next compressed between two slides and observed under the mi- 
croscope. Among the contents of the intestine, many lung larvae and 
larval skins were found. However, the larvae were all dead and seem- 
ingly had undergone digestion. Parasitism of thé worms themselves 
was found in two individuals. These showed, imbedded in the tissues, 
roundworms very similar to the lung-worm larvae in question. Re- 
membering, however, that all were equally exposed to infection and that 
only these two specimens were found parasitized, any conclusions de- 
rived from this experiment must necessarily be unreliable. Such para- 
sites as were found could have been acquired before the worms were 
placed into the soil cultures. 
In conducting the experiments with rats, four individuals were 
used. Two of these were fed lesions containing lung-worms at inter- 
vals of one week apart for a period of four weeks. The other two 
rats were fed larvae in advanced stages of development, and at ap- 
proximately the same intervals, for a period of ten weeks. After one 
month the first two rats were killed and found free from infection. 
The other pair of rats was killed three months after the first, and two 
weeks after the last feeding. These had very typical verminiferous 
lesions in both posterior lobes of the lungs. When these lesions were 
examined, numerous dead larvae and cast skins were found within 
them. No living larvae were found. 
An examination of the rat faeces showed that most larvae were 
excreted within the first 24 hours. In faeces of the first pair of rats no 
larvae could be found after the second day of feeding. In the case of 
the other two rats, the larvae persisted for four days. A large portion 
of these last seemed to have escaped digestion, but no living larvae 
were found. 
Blood samples of these rats were taken at different times, but 
gave negative results. 
TABLES. 
Experiments with Intermediate Hosts. 
Species Number Results Completed 
Examined 
Colliphora erythrocephala (Blue-bottle Fly) a 35 Negative 1920 
Sept. 22 
Musca domestica (Common House Fly).. ; 67 . Sept. 27 
Haematopinus suis (Hog Louse) ............. uf ; 47 A Sept. 28 
@ypris' candida, 4 wc. aars gattaccle ae 19 . Oct. 9 
Gyclops a maces yeeek eis eee are etter martes ites ae 22 . Oct. 11 
Earthworms. . . EE, Dr Mantes are ae eel we 17 ? Oct. 27 
White Rats : RRR Ce sae nee Weert s ; 4 Positive May 9 
