3 1 8 Massee and Salmon . — Researches on 
spore. These germ-tubes at the end of two days "had grown 
to strong branched long hyphae (Fig. 56). The exospore 
showed a tendency to break up in strips, as is figured by 
Janczewski (18) for the germinating spore of Ascob . furfur a- 
ceus. In a control experiment with spores of the same form 
of A. glaber at a temperature of about 6o° F. not a single spore 
had germinated at the end of twenty hours, although subse- 
quently slight germination occurred in many of the spores. 
As illustrative of the readiness with which the spores of this 
white form of A. glaber germinate, the following fact may 
be mentioned. Some rabbit-dung, bearing a rich crop of the 
above Ascobolus , was kept in a tin box. As the asci became 
ripe the spores were thrown on to the side of the box, where 
they germinated, and formed a mycelium which eventually 
produced apothecia. In a second set of experiments, with 
spores of A. perplexans in a hanging-drop of dung decoction 
at 8o° F., germination was vigorous ; but under the same 
conditions as above, except at 6o° F., no trace of germination 
occurred. In a hanging-drop of dung decoction with addition 
of one per cent, of pepsin, temperature 85° F., germination 
was very vigorous. In a second culture similar to the last in 
constituents, but at 65° F., there was a mere trace of germina- 
tion. As a set-off against the above our failures to induce 
germination of the spores of other species of Ascobolus and 
those of other dung Fungi were numerous, and the only point 
that appeared in the series of experiments was that the higher 
the temperature the greater the success in securing germina- 
tion. This is what would be expected if it is an advantage 
that spores should pass through the alimentary canal of an 
animal, although we are inclined for the following reasons to 
look upon this factor as acquired. 
The spores of certain species of Ascobolus that do not grow 
on dung, but on wood, decaying vegetable matter, or on the 
ground, germinate readily under artificial conditions, as shown 
by Boudier (4), whereas, as already stated, the spores of dung- 
borne species as a rule do not germinate at all under similar 
conditions ; nevertheless these highly specialized dung species 
