225 
Iu the ascus, or in water, the spores send out long tubes within 
24 hours, and produce sporidia in 48 hours, after which they perish. 
These sporidia occur in great numbers (see also Brefeld, IV., PI. IX, 
Fig. 16-19), but are functionless. The case is otherwise on nutrient 
media. The author used a decoction of raisins, solidified by the addi¬ 
tion of gelatine and sterilized by discontinuous heat. This substratum 
is easy to prepare and very suitable for the development of mucedi- 
neous facultative parasites. By germinating the ascospores on slides in 
drops of this gelatine and transferring the mycelium after four days to 
.Van Tieghem cells, the bottoms of which were covered with gelatine, 
he obtained a most luxuriant growth, but no sclerotia during the whole 
life of the mycelium, which exceeded three months. 
This fungus needs a start before it is strong enough to attack healthy 
tissues. Infection takes place by means of the mycelium, and hence, 
except in rare cases, it is possible only through the parts underground. 
Ascospores sown on fresh cuts of different rhizomes gave no results; 
but two rhizomes taken from the same pot were quickly infected (in 
four days) and destroyed with the usual symptoms, by bringing them 
into contact with some mycelium taken from one of the cell cultures. 
When the spores find their way into the soil ; especially when they 
lodge on the posterior decaying end of the rhizone, they are undoubt¬ 
edly in a condition favorable to robust growth, and have an excellent 
opportunity to attack the plant. 
Dr. Wakker discusses the relation of P. tuberosa to P. bulborum , which 
attacks hyacinths and related Liliacece in the same locality. The chief 
difference lies in the size of most of the organs, those of P. bulborum 
beiug smaller. The spore measurements, however, are identical, so 
that he would be inclined to doubt the specific difference were not the 
conviction universal among horticulturists that the disease never passes 
from hyacinths to anemones, or inversely. 
The ascus form is common in P. tuberosa. In the hyacinth disease, 
and other sclerotial diseases, the Peziza cups rarely develop. For this 
reason, and others, the author inclines to believe that P. tuberosa is the 
species truly indigenous to Central Europe and that P. sclerotiorum and 
P. bulborum are derivatives from this original stock, changed conditions 
having produced slight modifications, forming distinct but very closely 
related species. 
(II.) The author is able to throw some additional light on the gummo- 
sis of the hyacinth. He has also discovered gummosis iu the tulip and 
in Tecophilea cyanocrocus. A similar degeneration also occurs in Ixia 
bulbs (Dr. Masters) and in Cyclamen leaves (Prillieux). 
The very small gum pockets in the substance of the inner scales of 
the hyacinth are pure white, and their walls are still composed of living 
cells. These pockets are not limited, however, to the youngest scales, 
but invade even the outermost tunics and are often large, the walls be¬ 
coming dead and structureless and the gum exuding on the surface of 
