Microscopic Studies of the Water of the 

 Claremont-Laguna Region 



CESEVEIVE CORWIN 



The climatic conditions in Southern California where these studies were made, 

 are unusual in that the rainy season occurs during the winter and early spring and 

 there is practically no rainfall for the rest of the year. About 10 to 15 inches is the 

 average yearly amount. V\'ith this small amount of precipitation, most of the 

 streams dry up completely and the permanent pools diminish in size. This fact has 

 a profound effect upon the life contained in the water. Just how this effect works 

 out has not been determined. Some forms are able to dry up and still retain life, 

 while others are killed by lack of moisture. Almost all the studies recorded in this 

 paper were made on permanent pools and streams. 



Studies of the microscopic life of the Claremont-Laguna region were made in the 

 early spring and summer, those of the Claremont region in February, March and 

 April; and of the Laguna region during the last half of June and the month of 

 July of the previous year. 



Considering the two places as a whole, in general there were more green algae 

 than blue-green; more algae than Protozoa, the amoeboid Protozoa being fewest in 

 number; the flagellate a little more numerous and the ciliate most frequent, both in 

 species and individuals. The rotifers were rather rare, but were quite varied in 

 form, from the simply constructed, active Cnlurus to the beautifully ciliated fixed 

 Floseularia. The Castrolricha were very rare. 



The chief difference between the Caremont and the Laguna regions is the abun- 

 dance of aquatic life. This might be caused by the fact that most of the pools 

 studied around the Laguna were close to the shore and the water may have been 

 brackish. As a rule they were more stagnant than the Claremont water, with the 

 exception of the Laguna Lakes. Perhaps the seasonal change may have had some- 

 thing to do with this difference. The Claremont studies were made over a period 

 of time twice as long as the other and much earlier in the season. However this 

 may be, in almost every group there were more species in the Claremont region 

 than the Laguna and in all other cases there were at least as many, with the 

 one exception of the one desmid found in Claremont and not in Laguna. To 

 summarize the comparison: There were twice as many species of algae in the Clare- 

 ment region as the Laguna; the same number of blue-green for both localitis but 

 four limes as many green in Claremenl. The diatoms were quite numerous and 

 varied in form in both places but there were only half as many species in Laguna. 

 As mentioned before, one desmid was found in Clarement and none in Laguna. 



The Protozoa were quite abundant in both regions, there being three times as 

 many in Claremont as in Laguna. In Claremont the amoeboid were twice as 

 numerous as at Laguna. There was a larger proportion of beautiful complicated 

 forms in the Claremont region. There were three species of Sitnlor in Claremont 

 and only two in Laguna. The restless little Euplotn, the graceful Spiroslomium, the 

 beautiful Slylonye/iia are illustrations of the variety of ciliates in Claremont. 



