226 Brown : Algal periodicity 



Stream no. I is a small stream that flows across the University 

 campus. Above the campus it has the characteristics of an ordi- 

 nary small stream flowing across the country. During the greater 

 part of the year this flows briskly with a considerable volume of 

 comparatively pure water. After the stream enters the campus it 

 is greatly changed. It receives the warm water from the bathing 

 rooms, the refuse from the chemical laboratories, and the sewage 

 from the closets in the university buildings. This part flows the 

 whole year. The conditions of the two parts of this stream 

 being so radically different, it may be considered as two different 

 streams. This stream is shaded but little, has grassy banks, and 

 and but few of the higher plants grow in it. A few frogs are 

 found here, snapping turtles, mancelli, and planarian worms. On 

 October 3 1 the water in the stream above the campus contained 

 .015 g. solid matter in 40 g. of water, or .0037 per cent. 



Stream no. 2 is a small stream of cool, clear, pure water flow- 

 ing through a wooded valley about one fourth of a mile long. It 

 is fed by the outflow of an underground river. The flow of the 

 stream is rapid and continues throughout the year without much 

 variation, the temperature being very uniform, standing about 

 12 C. The plant life, aside from the algae, is limited to an 

 aquatic Pore/la, and the only animals found here are a few fish, 

 crayfish, gammari, and planarian worms. 



Of all the orders of algae found growing in the ponds and 

 streams under observation the order Conjugatae was the most 

 abundant both in quantity and in distribution. Among the forms 

 of this order, Spirogyra was the most abundant. It was found m 

 some quantity in all the ponds and streams except in the pond no. 1 



Several different species of Spirogyra were found. However, 



it was often difficult to determine the species when in vegetative 

 state. But several of the most common forms were seen fruiting 

 at some period. In that stage they could be easily identified. 

 Spirogyra nitida was the most abundant form throughout the year, 

 appearing in considerable quantity in all the ponds and streams 

 except ponds nos. 1 and 5 and stream no. 2. This species was 

 most abundant throughout the year in pond no. 3 (figure I 

 chart, pond no. 3). . In September it was rather rare, floating and 

 healthy. For the next few weeks there was not much change 



