486 KARLING: GROWTH AND REPRODUCTION IN CHARA 
Within wide limits the response is not dependent on the 
intensity of illumination under the conditions observed. A 
continuous illumination of less than ten foot-candles is sufficient 
to induce the development of antheridia and oogonia within 
four days 
Goowth under artificial illumination, as used in my experi- 
ments, led to the lengthening of the internodes, shortening of 
the leaves, reduced branching, etiolation, and a general spindling 
habit in the plants. Very few of the eggs developed into mature 
oospores. 
Under the conditions studied, the temperature, within the 
minimum and maximum limits for vegetative growth, is appar- 
ently a secondary factor in determining the production and 
functional activity of antheridia and oogonia in Chara fragilis. 
The writer is indebted to Professor R. A. Harper for his 
assistance and advice in this study and in the preparation of 
this paper. 
Literature Cited 
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