9 
organisms require certain natural situations ahd conditions 
such as heat and moisture, and if too hot or too cold, the 
germination is suspended or destroyed. But when in a 
favourable position and suitable temperature—like the yeast 
plant—development goes on readily. Professor Simonds has 
also tried to produce the disease in sound animals by giving 
them large quantities of the ova collected from rotted sheep, 
but failed to bring on the malady, proving that the flukes 
were not developed directly from the ova within the sheep in 
which they were deposited, but that the ova were required to 
pass through certain forms out of the animal before they 
could be again generated' into ultimate flukes. When the 
eggs left on the ground find the necessary surroundings for 
their incubation, the internal granular matter assumes a cel¬ 
lular form and in time small embryos of a cilliated character 
are developed which when fully matured make their escape 
from the shells by pressing open the lids or caps, and if 
immersed in water commence to move about in a jerking 
fashion, the small cilliae around their bodies aiding in this 
motion, seeking for objects for attachment to undergo further 
change, when, it is presumed, they gain access to 
molluscs as nurses, and are further transformed into sacs 
of bags, called by naturalists cevcavicc sacs or sporocysts, 
when the internal parts undergo division and small sporules 
or larvae are formed. These, when fully developed, it is 
thought, again make their escape out. of the sacs and look 
for other foster-parents for further transformation which 
by boring their way into small water snails or slugs wherein 
they roll themselves up and pass into the pupal form, throwing 
off from the body a secretion which hardens and encysts them, 
and in this form are supposed to be taken up with the food 
into the stomachs of the animals, when the hardened secre¬ 
tion becomes dissolved by the fluids of the first, second and 
