Semi-Centenvial Volume. 169 



Table III shows the seasonal distribution and frequency of the vari- 

 ous {genera of algae. Althoujjh there were but thirteen genera of diatoms 

 classified, they appeared 182 times, while the twenty-three genera of 

 Chlorophyceae were found only 114 times. Eleven genera of Myxo- 

 phyceae were found 167 times. The grand total indicates that the 

 fifty-one genera of algae appeared 486 times throughout the survey. It is 

 of interest to note that, although the specific genera varied from season 

 to season, the number of genera remained quite constant. During the 

 period of my observations the season of the year did not seem to have any 

 such relation to the species found, as Transeau (21a) discovered in his 

 study of algae of the pools and ponds of central Illinois. This may be 

 due to the artificial conditions brought about by the chemical treatment 

 and dredging of the reservoirs. The length of time necessary to estab- 

 lish such periodicity in artificial conditions might be greater than ir 

 natural conditions where observations were carried on for seven and a 

 half years. 



Of the many cases handled by the workers in the water laboratory, 

 the following instances show the value of the copper-sulfate method of 

 removing algje from the reservoirs in Kansas. 



In June, 1916, the water at Horton, Kan., was in bad condition, accord- 

 ing to' Supt. W. W. Wood. The author made a trip to Horton and found 

 the water had a disagreeable odor and a dark, reddish-brown color. This 

 color could not have been due to iron, since laboratory diagnosis had 

 shown no iron present. The reservoir was found to be covered with a 

 decaying mat of Cladophora, Spirogyra, Zygnema, Mougeotia, Anabaena, 

 Closterium, Euglena and Characium. The odor of the water in the reser- 

 voir, as well as the color, was due to these decaying forms. The settling 

 basin showed a count of sixty-eight organisms per cubic centimeter of 

 water, forty-nine of which were Anabaena. The basin, with a capacity of 

 600,000 gallons of water, was treated with two and one-half pounds of 

 CuS04 and allowed to stand for twenty-four hours. The supply of the 

 basin was changed from the infested reservoir to the creek, whose over- 

 flow supplies the reservoir and whose waters at that time were compara- 

 tively free from algae. In forty-eight hours all odors and color had dis- 

 appeared from the water in the basin. 



In the fall of 1916, the Olathe water system was infested with heavy 

 growths of Conferva. Much of the dense entanglement was raked out 

 upon the banks and the water was treated at the rate of six pounds of 

 copper sulfate to a million gallons of water. The water was usable within 

 three days. 



Russell, whose impounding reservoir has a capacity of 39,000,000 

 gallons, was troubled in September, 1916, with heavy growths of Ana- 

 baena, Conferva and Cladophora. The lowering waters had left a carpet 

 of decaying algae about the edge. The reservoir was treated with 50 

 pounds of copper sulfate distributed from a sack at the stern of a boat, 

 the banks were sprayed with about 100 pounds of the CuSO^ in solution. 

 No further trouble was reported. 



In March, 1917, Burlington reported a bad taste to the city water and 

 offensive odors rising especially from the filter beds. Analyses showed 



