6g8 
Journal of Agricultural Research 
V6I. XXIII, No. 9 
produced in the culture tubes themselves in the winter time, whereas in 
both the summers of 1919 and 1920 this phenomenon occurred regularly. 
That temperature was one factor involved in this seems evident, for the 
observation was made repeatedly that at the lower temperatures, even 
with good light and moisture, apothecium production was slow and the 
stalks were abnormally thin and the cups not well opened out. It was 
evident as well that light was involved. Preliminary experiments were 
started in November, 1920, to investigate this point further. 
Experiment XII.—November, 1920. Mature sclerotia were taken from several 
different tubes and evenly divided between two 250-cc. Krlenmeyer flasks, each 
containing 100 gm. of sterile sand and 25 cc. water. Thus the conditions were as 
near alike as possible. One of the flasks was then wrapped completely in black paper. 
Both were placed under a bell jar on the laboratory table with a dish of water beneath 
in order to keep the humidity high. A 60-watt Mazda light was placed about 18 
inches to one side and was kept lighted every night for several weeks. The nearness 
of the light was adjusted until the temperature within the bell jar was about 25 0 C., 
which had been shown to be the optimum for development of the fungus. For a 
long time no development occurred. After two months, however, numerous apo- 
thecial stalks commenced to rise from the sclerotia in the flask exposed to the light. 
These attained considerable length, in some cases at least 2 cm., and all leaned very 
strongly toward the source of light. None of them opened out into normal apothecia, 
however. In the dark flask no development whatever occurred. 
Experiment XIII.—December, 1920. After this very clear demonstration of the 
influence of light was observed, a further, more extensive series was started, with 
the cooperation of Mr. H. A. Allard, who very kindly consented to the use of his con¬ 
trolled light conditions (p) in the greenhouse at Arlington Farm. This was primarily 
a length-of-day experiment, and involved the turning on of electric lights at dusk in 
the evening, leaving them on long enough to make the day the length desired. Eights 
of different intensities were used, the intensity being determined by the nearness 
of the light to the subjects of the experiment. Two flasks each, prepared as described 
for experiment XII, were placed under four different conditions: (1) a 20-hour day, 
the source of added light being small Mazda lamps near the roof of the greenhouse 
several feet away from the flasks; (2) a 20-hour day, the added light being a 100-watt 
lamp about a foot distant from the flasks; (3) a 20-hour day, with a 100-watt lamp 
about 3 feet distant; (4) the normal day for that time of year, approximately 9 horns. 
In addition, a flask prepared like the others in all respects was covered completely 
with black paper to shut out all light. Temperature and moisture conditions were 
as nearly alike as could be maintained under ordinary greenhouse management. 
The sclerotia in the different lots were from identical sources, and included some 
from nature as well as from artificial cultures. Observations were made once a week, 
and for three weeks no change was to be seen in any of the flasks. On the fourth 
week one flask of lot 3 showed early stages of apothecial formation. Six weeks after 
the experiment was started mature apothecia were found in all the flasks subject 
to increased day length, the largest and best specimens being found in lots 2 and 3, 
while in the flask under ordinary daylight conditions a few spindling stalks had arisen, 
which never opened out. The sclerotia in the dark container had not developed 
the slightest suggestion of an apothecial stalk. 
This experiment again shows the influence of light on the germination 
of sclerotia, but results are still far from satisfactory. The normal 
summer development of apothecia was not even approached under the 
artificial conditions that prevailed. It is to be hoped that some more 
work can be done along this line. 
PERFECT STAGE IN NATURE 
The first appearance of the perfect stage under altogether natural 
conditions was not observed until early in July, 1919. After a prolonged 
rainy period at Orlando, Fla., a careful examination was made of castor- 
bean plants and of the ground beneath in the Boardman field. Several 
apothecia were found arising from sclerotia that had fallen to the ground. 
