Hazen: Lire HISTORY or SPHAERELLA LACUSTRIS 215 
I first collected this alga at Burlington, Vermont, in hollows of 
a red sandstone quarry where it had been obtained during several 
seasons for the use of classes in biology at the University of Ver- 
mont. I also found it in similar hollows of limestone ledges in 
the vicinity. I have made a careful study of these pools and found 
that in all cases they were small basins filled by rain or water ooz- 
ing from the ledges above, but so shallow as frequently to be dried 
up during the summer. Similar but deeper basins side by side 
with these contained Hydrodictyon and Spirogyra, but no Sphae- 
rella. The apparent reason was twofold: (1) The deeper pools 
did not furnish the condition of frequently alternating wetness and 
dryness which culture experiments show is favorable for prolonged 
vitality, and (2) If the Sphaerella did cover the bottom of these 
deeper basins as they dry up in the hottest weather, when they are | 
re-filled by a heavy rain the cells would be so deeply buried as to 
be unable to get sufficient air for development. 
Professor G. H. Hudson has sent me Sphaerella material from 
Plattsburgh, New York, where he collects it in hollows of an aban- 
doned quarry in Chazy limestone and in a pot-hole of the Saranac 
River ; he says * these pools become dry in summer and the stones 
look as if red paint had been spilled upon them." 
Sphaerella is rather abundant in rock hollows near streams 
and about the lake at Ithaca, New York. Material collected there 
in December by Professor F. A. Waugh divided so rapidly that after 
two weeks I found all the zooids were of a comparatively small size. 
Professor W. L. Bray has sent me material from Austin, Texas, 
where it is found in a pond which lasts almost all the year, form- 
ing part of a creek in winter, and also in creek pools near the Colo- 
rado River. Chodat ('97) finds that Haematococcus is present 
though not abundant even in the plankton of Swiss lakes, but he 
considers that in such cases it has been washed out of the rock 
basins which form its natural home along the shore. 
I have Sphaerella material obtained in cemetery urns in Chicago 
by Professor C. B. Atwell, and in Baltimore by Mr. H. F. Perkins. 
Professor E. G. Conklin has also found it in such urns in Delaware, 
Ohio, Evanston, Ill., and Philadelphia. A note in Dr. Harriet 
Randolph's ** Laboratory Directions in General Biology " suggests 
that the occurrence of Haematococcus in marble urns may be due 
