PAPERS OX BIOLOGY AND AGRICULTURE So 



PEESENCE OF LIVING ORGANISMS IN LAKE ICE 



Samuel Eddy, James Millikix University 



The object of these experiments and observations was 

 to determine what forms of life were existing in the ice 

 of Lake Decatur. Lake Decatur is an artificial Lake 

 seven miles long and one-half mile wide, created by dam- 

 ming the Sangamon river. The depth of the water varied 

 from a few inches to forty feet. The periods at which 

 the materials were collected were during zero weather 

 when the Lake was entirely frozen over. The thickness 

 of the ice ranged from eight to twelve inches. 



On January 7, two samples of ice and two samples of 

 water from below the ice were collected. The ice was 

 taken from the surface near the shore and from the cen- 

 ter. Each sample was immediately placed in sterilized 

 bottles containing sterilized hay infusion and plugged 

 with cotton. The samples of water at a temperature of 

 1 -2 degree Centigrade were taken from the holes from 

 which the ice was cut. The samples were placed in simi- 

 lar bottles and under the same conditions. A sample of 

 mud from near the shore was also treated in the same 

 manner. In the cultures from the ice and hay infusions", 

 observations were made January 23, January 28, and 

 February 6. On all these dates various bacteria were 

 common. The only other form of life observed was 

 Chlamydomonas which was present in small numbers on 

 January 23, but multipled rapidly enough to be common 

 on the other observation dates. In the cultures from the 

 hay infusion, and lake water or mud examined under the 

 same conditions on the same days, Chlamydomonas, 

 Urosomas, Chilomonas, Coleps, Pleuronema, Stilonichia 

 and many other unidentified protozoa were observed. 



On January 25, two samples of ice, four of water and 

 two of mud were collected and treated the same as those 

 collected January 7. Xutrient agar was substituted for 

 the hay infusion. Observations were made January 31 

 and February 7. The results were practically the same. 

 Chlamydomonas and bacteria were the only forms of life 

 in the ice cultures. Chlamydomonas, Leucophrys, Para- 



From the Department of Biology, the James Millikin University. No. 2. 



