Investigations in 1889/0;' the Royal Agricultural Society. 191 
Fip 
was produced, and the animals were not in any way protected from 
an attack of the natural disease. 
The Lung-v;orm. — The investigation into the life-history of the 
lung- worm, which causes husk in calves and lambs, was continued 
during the year, and some very curious results were obtained, which 
for the purposes of this report may be summarised. 
It has already been stated that the embryos of the lung-worm 
find a temporary habitat in earthworms, in which they undergo deve- 
lopment. It is certain that at least three varieties of threadworms 
are entertained by these accommodating hosts, the earthworms, 
and one variety, the an- 
guillidre, becomes sexually 
mature before being ex- 
pelled by the worm. Dur- 
ing the spring and summer 
months earthworms have 
generally been found to 
be free from embryos of 
strongyles, but, as soon as 
the husk appeared among 
sheep and lambs, the 
earthworms furnish em- 
bryos in abundance ; the 
presumption, therefore, is, 
that after attaining a cer- 
tain stage of development, 
the embryos have migrated or been expelled from the bodies of 
the earthworms, and remain among the roots of the grasses, ready 
to be taken up by calves and lambs grazing upon them. As soon as 
the lungs become invaded by the mature strongyles, eggs containing 
living embryos are expelled in large quantities, and are swallowed 
by the earthworms, in whose bodies they remain until they are 
sufficiently developed, when they are expelled, and live in the damp 
earth or in the roots of grasses, and are thus ready to produce 
another outbreak of disease in the following season. 
Among the embryos of the threadworms, other organisms have 
been found in the digestive tubes of the ■earthworm, for instance 
the ova of a small freshwater snail as shown in the illustration (Fig. 3). 
The Action of Ergot. — Some in-calf heifers were selected for these 
experiments, and, by a fortunate accident, one of them suffered 
from abortion before a single dose of the agent had been administered. 
Otherwise, had the experiments been commenced a few days earlier, 
it would have been difficult to avoid the conclusion that the ergot was 
the cause of abortion. The dose which was given to the experimental 
animals was a quarter of an ounce of the freshly powdered 
ergot daily for some time. Afterwards the dose was doubled, 
without any result whatever. One animal received a consider- 
able quantity of ergotised grass, which was forwarded by Mr. 
Whitehead, but no disturbance of any kind was occasioned. Ex- 
periments are already on record in which enormous quantities of 
-Ora of freshwater snail found in 
intestine of Earthworm. 
