KARLING: GROWTH AND REPRODUCTION IN CHARA 471 
of C. hispida grown a meter or more from a window, Miiller 
(26) found plants in which some of the internodes were without 
corticating cells. He also grew cultures of C. foetida in dark 
and half-dark rooms and in full daylight. In many of the plants 
grown in reduced illumination the corticating cells were either 
absent or abnormally arranged about the internodes. In such 
cases, the corticating cells, instead of adhering closely to the 
internodal cell, formed a loose sheath. Miiller, however, made 
no experiments involving the lengthening or shortening of the 
period of illumination. 
Nonweiler (27) grew Chara strigosa with peat and sand as 
substrata in sodium chloride solutions of various concentrations 
in full and reduced illumination. Increased concentration of 
the solution reduced the length but increased the diameter of 
the internodes. He observed that high temperature and light 
intensity hindered length growth. Ernst (14) reports that the 
length of the oospores of Chara criniia varied considerably with 
changes in temperature and light intensity, culture medium, 
and substratum on which the cultures were grown. Cultures 
grown under double-walled bell-jars with potassium bichromate 
and with ammoniacal cuprous oxide solution, or in reduced 
illumination, produced shorter oospores than in normal cultures. 
Hodgetts (21) in his study of the periodicity of fresh-water algae 
in nature reports that Nitella flexilis develops most rapidly 
when the temperature is moderately high, and that abundant 
bright sunshine is very necessary for oospore-production. 
CHARA FRAGILIS GROWING IN NATURE 
The plants used in the following experiments were secured 
from a small, shallow pond in Van Cortlandt Park, New York 
City, during the interval between September, 1923 and April, 
1924. This is apparently an unreported locality for Chara in the 
vicinity of New York City. The water in this pond during winter 
of 1923 and the early summer of 1924 was shallow (5-20 cm. deep) 
and during June and July when the vegetative growth appeared 
most vigorous, the plants did not attain a length over 45 cm. 
The growth from October to March was negligible. It seems 
probable that when the winter is severe the tops of the plants 
may be killed by freezing. In such an instance, the nodes and 
other parts of the plants buried in the soil give rise to the next 
year’s growth. 
