THE REPRODUCTION OF A8COMYCETES. 
135 
become oval ; the concave part of the arc fills out, and the general 
form of the spore is completely modified ; the plasma, which was 
very dense and withoutglobnle, appeared more clearly characterised. 
One perceived, upon the principal borders, some granulous traces 
and some outlines of vacuoles. A little later, after four or five 
days, the spore emitted one or two short and deformed filaments, 
the diameter of which differed a little from the transverse diameter 
of this same spore after its swelling out. 
In this state one sees that the germination is very clearly com- 
menced ; but the more often, the nourishment is appropriated 
badly, only sufficing to determine this dehut of development, not 
allowing it to go further on. There also exists bacteria which 
have multiplied, and the presence of which in the preparation 
singularly obstructs the march of experience. Upon many pre- 
parations disposed with the same spores and the same liquid, some 
arrive well, whilst others only give place to some strange produc- 
tions. This irregularity is not one of the least difficulties that 
one has to deal with. 
In each case a comparative attempt was made in pure water, but 
never brought forth any results ; by the side of the cell in which 
the sowing was placed in a nourishing liquid, and in which, in 
identical conditions, a sowing was tried in pure water. Upon all the 
species studied the comparison was established, so as to show the 
difference of the developments. The Diplodia vulgaris^ developed 
upon the Crataegus oxgacantha, gave absolutely analogous results, 
although the development appeared noticeably more slow ; it was 
the same with that of the lime-tree {Diplodia). 
The sperm atia of Valsa leucostoma were gathered upon a 
branch of peach tree, and they were sown simultaneously in the 
same nutritive as before, and in pure water. In the water the 
spores remained without changing during many weeks ; in the 
nutritive liquid, on the contrary, in about two days these spores 
had completely modified their form : slender, disposed in an arc, 
they were becoming irregularly oval, and were already noticeably 
elongated. But after four days they were not recognisable ; they 
had taken the appearance of deformed filaments, upon which one 
could hardly see, in certain cases, the spore which had given them 
birth ; but they did not continue to elongate, want of nourishment 
probably. 
The Valsa liphcemia, common upon the oak, offers spermatia 
of the same form. Sown under the same conditions, these 
spermatia increased in size, slowly remaining more or less pointed 
at one of their extremities. Their bigness was very unequal ; at 
about the seventh day these spores had increased more than ten 
times in volume ; after fourteen days they had still got bigger, 
some of them presenting appearances of prolongations, but not 
clear. In pure ivater they had no development, no modification of 
any sort. 
