51 
September, 1907. In order to get a perfect blood rela- 
tionship ova and embryos were placed in the crops of 
newly-arrived parrots which had been tested by the im- 
proved method and passed. Another parrot is kept in 
a cage soiled by a verminous bird. One bird died in 
four weeks with pneumonia. It showed no worms. The 
others are examined regularly and so far have shown no 
ova in the stools. 
These failures, along with the sluggish motions of the 
larvae, suggest the necessity of an intermediate host. If 
an intermediate host is necessary it will complicate the 
determination of the life history. Once discovered, 
however, it will furnish a point of attack for hygienic and 
prophylactic measures. 
The first host that suggested itself was the cockroach. 
These along with mice and rats have been obtained from 
the bird house and examined in past years by Dr. Smith 
and Dr. Fox with negative results. About twenty of the 
small German variety were examined by us with similar 
results. Some were fed with spiroptera eggs and exam- 
ined at intervals. The eggs were found in the intestine 
but had undergone no changes. The readier hatching 
in pigeon serum suggests that this is a suitable environ- 
ment. Experiments are proposed in which eggs and 
newly-hatched embryos will be placed in abrasions of 
the proventricle. The mice and larger (Australian) cock- 
roaches are kept in mind and may later on be fed on the 
eggs and kept in cages with pigeons. The possibility of 
transference by an insect bite is remote. The blood of 
birds dead with worms has been repeatedly examined 
with negative results. The same is true of blood from 
living verminous birds. 
The most rapid hatching occurred in a corked vial of 
tap water at room temperature, in which a female had 
been placed to deposit her eggs for subsequent experi- 
ments. Four days she was found ruptured, her egg 
tubes protruding and also ruptured. In them were 
worms in all stages of hatching, some starting, some 
partially, some finished. 
