99 



SUMMARY. 



Tlie result!" of tliis experiment show conclusively: 



That the Bordeaux mixture, properly applied to the plants during their period 

 of growth, does materially lessen the smut. 



That the ammoniacal copper carhonate was not as effect-ive as the Bordeaux 

 in preventing the smut. 



That freipient applications of the fungicides are necessary during the growing 

 {seriod of the plant in oj-der to he effective. 



A Xeav Station for Pleodorina Cai.iforkica Shaw. By Severance 



BfRRAfiE. 



During an investigation of the sanitary condition of the Wal)ash and Erie 

 Canal as it runs through Lafayette, made in the laboratories at Purdue in Sep- 

 tember of the pre«ent year, Pleodorina was found in considerable abundance in 

 the canal water. This comparatively new member of the Volro.r family was first 

 described l)y Walter R. Shaw, of Leland Stanford University, who found the 

 plant in a ditch in Palo Alto in September, 189o ( " Botanical Gazette," Vol. 19, 

 p. 279). Since then D. M. Mottier has reported it in Bloomington, Indiana, 

 in May, 1894, and Messrs. Clinton and Burrill in Havana, Illinois (" Botanical 

 Gazette," Vol. 19, p. 383 ), in June of the same year. It is now possible to add 

 another station in Indiana, namely, Lafayette. 



The microscopical examinations were made according to the Sedgwick-Rafter 

 method, Avhich has been used for several years by the Massachusetts State Board 

 of Health iii the enumeration of microscopical organisms, exclusive of bacteria, 

 in water supplies. The average number of Pleodorina in one cubic centimeter of 

 the canal water was four. The census of other organisms found in the same sam- 

 ples included, on the vegetable side, Ifi/drodiclion, Chara, and Spirogyra, too large 

 and abundant to enumerate; Diatoms, per cubic centimeter, eight; Oscillaria, 

 fifty-six; AiKibaena, three; Scewdesmtis, one; Protocuccufi, eight; Crenolkrix, ten; 

 Pandorinci, one; mold In/pltae, three; and, on the animal side, j)rincipally infus- 

 oria, as I'eridiiiiuni, two hundred and ninety-six; Monas, four; Traehelonvmas, 

 three; Dinohri/on, three; and a few Roti/era and Acarina. The water was (juite 

 turbid, and had the general appeai-ance of dilute sewage, and in fact the water of 

 the canal was evidently polluted. This shows the nature of the water in which 

 Pleodorina seems to flourish in Lafayette, and also many of its companions. 



