442 BULLETIN OF THE BUSSEY INSTITUTION. 
tions. ‘The filaments are more frequently simple, but sometimes branch. 
At the tip of the terminal joint, or more frequently a little to one side, 
is borne a spore, .006 mm. in length, ovate, and rather sharply 
pointed at the lower,end. Not unfrequently two or three spores are 
borne on the upper joint, and others may also be produced on some 
of the lower joints. We have never seen any cross divisions in the 
conidial spores, which fall very easily from their attachments. The 
conidia which we have just described spring directly from the surface 
cells of the perithecia. They continue to bear their spores until the 
latter part of summer, when they begin to dry up, and, as winter sets 
in, one finds only their shrivelled remains. The conidia, it will be 
seen, are of that form which constitutes the genus Cladosporium of — 
the older mycologists, or at times the threads are so flexuous as to 
remind one of species of Streptothrix. The genus Cladosporium, 
long ago lost all claims to autonomy, the forms included in it having 
been shown by Tulasne and others to be the secondary forms of 
different Spheriacee. Streptothrix, represented by S. atra, B. and C., 
a common species of this country, will in all probability soon share the 
fate of Cladosporium. 
Ascosporres.— As the summer advances, the knot grows larger, 
harder, and more brittle, and is usually attacked by insects of different 
species, which destroy the central part of the knot, leaving the black 
outer shell. y 
It is not until winter, however, that the spores are produced in 
the asci of the fungus. If we make a section of the outer part of 
the knot late in the autumn or early in the winter, we shall find that 
the perithecia are so far developed that one can see the young hyaline 
asci which line them. We have made no search for a carpogone, as 
it is evident that the fungus under consideration, owing to its dense, 
opaque substance, is one of the least favorable for the study of that 
organ. The asci grow slowly during the winter, and about the middle 
of January the spores begin to ripen. In the month of February, 
they are found in perfection; but late in spring they are not so 
abundant, or in such good condition. We first found a few ripe spores 
on the 17th of January; and, in the second week of February, most 
of the knots examined contained ripe spores. In the manner of their 
production in the asci, the present spores do not differ from those of 
the other Pyrenomycetes. ‘There are eight in each ascus, and they 
