Feb. 5,1917 
Leafspot-Rot of Pond Lilies 
227 
VIABILITY OF THE FUNGUS IN CULTURE 
In order to ascertain the viability of the fungus in culture under 
ordinary laboratory conditions transfers to corn-meal-agar slants were 
made from time to time during two years, and plates poured from old 
corn-meal-agar cultures. Tests were made of cultures 11 months old. 
None of this age were viable. With strains 205 and 225 three tests 
each were made at different times with cultures 3^, 4, 5, and 7 months 
old, respectively; and with 249, three tests with cultures months 
old, and one test each with cultures 5 and 7 months old. At the same 
time that transfers were made to corn-meal-agar slants, corn-meal-agar 
plates were poured from each of these old cultures so that germination 
could be followed under the microscope (PI. 69, A). Up to seven months 
every culture tested gave growth readily on corn-meal-agar slants and 
in petri dishes, and the colonies developed the typical conidia in abun¬ 
dance. Examination of the petri-dish cultures showed that germination 
occurred from both conidia and sclerotia. Two successful sets of inocu¬ 
lations were made on pond-lily leaves directly from cultures 45 days 
and 60 days old, respectively. In addition, transfers from a few of the 
3K> 4> 5> and 7 months old cultures were tested by inoculation on 
leaves of pond lily; and in each case typical infection resulted. This, 
together with microscopical examination, showed the colonies to be 
from the original fungus and not from an intruder. This would tend to 
show that the conidia and sclerotia are both capable'of carrying the 
fungus over for a considerable period of time under certain adverse con¬ 
ditions, such as drying and increased acidity of the medium, at tem¬ 
peratures ranging from 20° to 30° C. 
SCLEROTIAL GERMINATIONS 
Sclerotiafrom 1-, 3-, 6-, 8-, 9-, and 11-months-old corn-meal-agar cultures 
were sown on sterile moistened sand and sterile moistened garden soil 
and held at laboratory temperature (about 20° C.). Germination took 
place from all the sclerotia, except in the case of those from the 11- 
months-old cultures, but microscopical examination at intervals during 
three weeks failed to show any sporulating form in connection with them. 
Sections after two and three weeks showed the sclerotia still made up of a 
solid mass of fungus cells, hyalin in the interior and brownish and 
thick-walled on the exterior. This is the structure shown by both 
young and old sclerotia in culture (PL 67, C, E), and in no case have 
evidences of a pycnidial or perithecial stage been observed. 
Single sclerotia separated from mycelium and conidia and sown in 
fresh culture media readily send out germ tubes from the superficial 
cells (PL 67, D)y and successful inoculations to leaves have been made, 
using such isolated sclerotia. 
