98 ROYAL SOCIETY OF CANADA 
after starting this experiment I examined the interior of the cage again, 
I found the whole moss superficially and throughout the layer studded 
with fine whitish colonies of fungi. These were examined and found to 
be small colonies of Jsaria. These colonies remained up to date very 
minute, but never disappeared. New ones constantly appeared and at 
present the moss is peculiarly studded all over with minute /saria 
colonies. These colonies having no supply of congenial food remained 
small and were of course of starved appearance. I next separated a few 
and transferred them to a petri dish containing nutrient gelatine. Here 
they made three days’ rapid growth and no doubt would have covered in 
the usual way the whole surface but for the appearance of gelatine liquify- 
ing bacteria which put a premature end to my observation. Nevertheless, 
it was proved repeatedly that the fungous spots consisted of Zsaria 
farinosa and no other. It was surprising to me that, never throughout 
these experiments, I was able to observe other fungi; like Penicillium 
and other common moulds. Several important conclusions may be 
drawn from these experiments. 
1. Granted that the cocoons used in experiments A and B were in . 
equal condition as far as their being alive is concerned, it is shown from 
the greater number of adults or parasites emerging from cage (experi- 
ment A) and from the infection of a large proportion of cocoons in ex- 
periment B that the fungus Jsaria farinosa is truly parasitic on larch 
sawfly cocoons. 
2. It is evident that spore infection of the cocoons had taken 
place. On no occasion I observed the infection of adults; they died 
rapidly but remained uninfected. 
3. The fungus /saria farinosa is capable of vegetating saprohpy- 
tically for a considerable length of time, provided sufficient moisture 
is available. The conditions under which this mode of life was observed 
were close to natural conditions. 
4. Owing to this saprophytic mode of life there remains little 
doubt that the pupating larve of the larch sawfly infect themselves when 
taking to the ground for pupation. The colonies observed in the moss 
appeared about the end of July and continued to show up to the end of 
September, during which time, of course, the pupation of the larch sawfly 
takes place in nature. 
Itt, 
I have to record some observations on another experiment under- 
taken to discover whether it is possible to infect larch sawfly adults and 
cocoons with spores of /saria from pure cultures. For this purpose 
a flat glass dish containing Sphagnum was sterilized on three successive 
days in an hot air sterilizer. Although the moss became brown in colour 
