120 
into the stroma. It has, however, been shown that in Cytispora indi¬ 
vidual pycnidia may project beyond the stroma. As regards the arti¬ 
ficial ones we have only a variation dependent upon external conditions. 
To this correspond the relations of the spontaneous Cytispora upon 
other substrata than twigs. Spores of the same kind were sown upon 
a well sterilized wilted leaf. The result was a stroma with pycnidia, 
having exactly the same appearance of that produced upon the slide. 
Infections of living and dead branches with Cytispora spores were with¬ 
out result. 
It may also be mentioned that the circular arrangement of the pycni¬ 
dia upon the slide points to a Valsoid stroma. 
The beginnings of the pycnidia and their transformation into irregu¬ 
lar chambers can not be so easily studied in the natural as in the cul¬ 
tivated Cytispora. But the results .are in no way contradictory. In 
the natural Cytispora , also, the beginnings appear as knots of liyphae 
of a globose form, which are by the least growth of the stroma brought 
very close together, and consequently must change their form and even 
coalesce on further growth. 
What has been said suffices to show that there is no difference be¬ 
tween the Cytispora and the pycnidia produced upon the slide, and that 
such variations as are present are traceable to the conditions necessary 
in culture methods; the two are therefore homologous. 
Now since the beginnings of Fcnestella peritkecia have been formed 
directly upon the stroma of Cytispora , and the development of Cytispora , 
from the ascospore has been observed step by step upon the slide, the 
life history of the fungus is closed for us. That peritkecia should be 
produced under the conditions necessary to the culture method was not 
to be expected. They would likewise have arisen in the form of knots 
of liyphae within the circle of pycnidia. 
Although the pycnidia are extraordinarily small and spermatia-like, 
they possess the power of germination. In a suitable nutritive solu¬ 
tion the spores swell up greatly and develop two or three germ tubes, 
which are much enlarged at their bases, so that afterwards it is often 
hard to say which is the swelling and which the spore. They pro¬ 
ceed to branch like a budding fungus, afterwards one branch shows a 
strong growth at one end. Otherwise the mycelium develops in the 
same manner as from the ascospore. 
The life history of the-Fenestella is, however, by no means completed 
with what has been recorded. In order to prove whether the fungus 
was related to the Cytispora , sowings of the ascospores were made 
upon Platanus leaves and produced what is presumably a new stage of 
this pleomorphic form. 
The spores were sown in a drop of water and this placed upon the 
lower surface of fresh young leaves and these kept moist. Germination 
was observed in a few days, but the penetration of the germ tubes was 
not seen. The inoculated parts began to turn brown without the fungus 
