IKKARLING: GROWTH AND REPRODUCTION IN CHARA 481 
Culture E consisted of a jar of about one hundred and fifty 
shoots collected at the same time as those of Cultures B, C and 
D. It had been kept in the south window of the laboratory 
under the same light and temperature conditions as the three 
preceding cultures up to April 15. On that date the jar was 
transferred to a photographic dark room. The plants were il- 
CuHartT 2. Summary and comparison of cultures of Chara fragilis. 
HOURS ——$ 10 _11__12 18 _14 _15 18 17 _18 18 20 21 92 93 _24 
Asi That MR 26 
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o~s SECO GL OL8 PS GOS OS OLS, 
MR19 MR31 AP13 
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Hours of daylight at timeof starting each experiment. 
Hours of electric illumination in addition to daylight. 
Increase of hours of daylight due to advancing season. 
Decrease in hours of electric illumination due to increase 
in hours of daylight. 
" §—date of starting experiment. 
F—date of fruiting of culture. 
Hours of darkness. P—date of photographing culture. 
luminated with electric light continuously from April 15 to May 
7, receiving no daylight whatever. On April 19, four days 
after starting the experiment, rudimentary antheridia and 
oogonia were visible. By the end of the month they were full- 
sized and had begun to drop off and disintegrate. The produc- 
tion of antheridia and oogonia was more abundant than in any 
of the preceding cultures. Practically every leaf axil was full 
