NOTES ON THE OCCURRENCE OF OSCILLATORIA PRO- 
LIFICA (GREVIELE) GOMONT IN THE ICE OF PINE 
LAKE, WAUKESHA COUNTY, WISCONSIN." 
EDGAR W. OLIVE. 
The presence of this minute alga in Pine Lake is of particular 
interest since, so far as 1 am able to determine, it has been here¬ 
tofore reported from but one locality in America, viz., from 
Jamaica Pond, a smail lake in Jamaica Plain, a suburb of Bos¬ 
ton. Mr. G. J. Hansen called the attention of Professor Birge 
to the peculiar growth in Pine Lake, furnishing some notes on 
its occurrence, and sent to him material which he had collected 
on March 25, 1905, which was floating on the surface of the lake 
where the ice had melted. Dr. Birge in turn gave the matter 
into my hands for further examination. 
Isabel P. Hyams and Ellen H. Richards have had Osciilatoria 
prolifica under observation in Jamaica Pond since 1887, and 
their three papers on the subject so far published embrace the 
“Life History” (01); “Chemical Composition” (02); and 
“Coloring Matters” (04). It will be of advantage to review in 
considerable detail some of the long-continued studies of these 
writers in order to supplement our meager observations in con¬ 
nection with the occurrence in Pine Lake and thus be able to 
judge of the conditions which could bring about, in this instance, 
such an unprecedentedly vigorous growth of the plant. 
Osciilatoria prolifica was first noted in Jamaica Pond by these 
two writers in 1887, and since that time has been so abundant 
as almost to exclude other forms of plant life. In some years 
it was much more abundant than in others, dependent upon the 
*This work was done while the writer was serving as a research 
assistant of the Carnegie Institution of Washington. 
