PAPERS OX BIOLOGY AND AGRICULTURE 187 



empties cinders, thus helping to fill up the lake. The 

 pond if undisturbed vnll gradually fill up with humus 

 fomied by plants that die and by silt washed in by the 

 small stream. Besides the area above described, this 

 survey includes a swampy region about twenty feet 

 east of the east end of Lake Knox (a little road separat- 

 ing it from the lake). This area has developed in the 

 last five years. In this swamp are many cat tails, and 

 muskrat mounds are quite numerous. 



The reasons for choosing this particular pond for this 

 ecological survey were (I) because it is small and thus 

 better suited for making an extensive study; (2) because 

 it seemed likfe a typical place for the study of pond life ; 

 (3) because it is accessible, being not far from college and 

 on the street car line; (4) because of the great abundance 

 of aquatic life found there. 



The purpose in this study is to make as extensive a 

 survey as possible, in the limited time, of the fauna of 

 the pond and its life. An attempt has been made (1) to 

 study the enviromnental conditions which pertained to 

 the life of the animals ; (2) to identify by means of a key 

 the specimens found therein, and (3) to study their habits 

 in relation to their environment. 



Methods : In order to coUect systematically, definite 

 stations wei'e established from which specimens were 

 collected once a week by means of a long handled dip net ; 

 these -specimens, together T\T.th some of the mud, algae, 

 etc., were put in fruit jars and small bottles and brought 

 to the laboratory. The material was then examined; 

 some specimens were preserved at once in 70^"c alcohol 

 while some were kept alive in large jars for further study 

 of their habits, and development of laiwal forms. Most 

 of the collecting was done on Saturday, but the work of 

 study and identification was done during the week with 

 the aid of a lens, binoculars and microscope. 



Five stations were established. (I) The swiftly flow- 

 ing brick-bottomed stream, which entered the lake at 

 the southeast corner, together with the muddy area im- 

 mediately adjacent was selected. For this station an 

 area ten feet square was measured. (11) A shallow sta- 

 tion west of station I where the water flows in through 



