24 
Notable contrasts in kind and number appear between animals of 
the springy shore of river or lake, and those of the muddy bottom, 
only a few rods away on the other side; between river and lake; 
between Quiver and Thompson’s lakes; between each of these 
and Matanzas Lake; and between all the other lakes and the 
temporary pond distinguished locally as Phelps Lake,—contrasts 
sometimes easily comprehensible, as in the first instance given, 
where the cool spring water flowing in abundantly is evidently 
favorable tothe gammarids and aselli swarming there; and some- 
times peculiarly puzzling, like that between Quiver Lake on the 
one hand, whose waters were choked in midsummer with a dense 
growth of aquatic vegetation but contained fewer of the smaller 
animal forms (Entomostraca, and the like) than the open cur- 
rent of the river itself, and Thompson’s Lake, on the other 
hand, where the water was relatively clear of aquatic plants but 
abounded in rotifers and Entomostraca. Still more curious was 
the contrast between the similarly situated and very similar 
lakes, Quiver and Matanzas, the waters of one loaded and 
clogged with plants and swarming with small mollusks and in- 
sect larve, and those of the other with scarcely a trace of even 
microscopic vegetation, and with a correspondingly insignificant 
quantity of animal life. 
The course of events in a body of water like Phelps Lake, with 
its terrific seasonal vicissitudes, ranging from complete overflow 
and loss of identity to absolute drying away in now and then an 
exceptional year, is extremely interesting to the cecologist. The 
extraordinary instability of the system, one predominant and 
excessively abundant form quickly following another almost to 
the suppression of its predecessor, and all finally overwhelmed 
in acommon doom, gives to the student an impression of an 
unhealthy organism, caught in the trap of an unfavorable envi- 
ronment, and hurrying through the stages of a fatal disease. 
One of the surprises of the season was the abundance of 
minute life in the main stream, which, as already intimated, 
sometimes contained a greater abundance of animal forms than 
most of the lakes connected with it; and another was the rela- 
tively small difference between the animals frequenting widely 
unlike situations in the same body of water. This is not the 
place, however, for a summary of our discoveries, and I must 
content myself with the statement that the freshness and fruit- 
