*.)8 Sovie A/gaof MtHnesota — Arthur. 



collected by the wind. That some of the aiiiiuals had drunk of 

 the water and scum a few hours only before they died was posi- 

 tively known, and that all had done so seemed from the circum- 

 stances quite probable. After the most careful examination the 

 only plausible hypothesis that could be advanced to account for 

 the death of the animals was that the alga present possessed some 

 toxic or other baneful properties sufficiently powerful to kill a cow 

 in a half hour <;r more after drinking freely of it. The well-estab- 

 lished reputation of all the alga? for innocuousness made this 

 hypothesis appear from the very first extremely improbable, but 

 for want of the slightest hint in an 3^ other direction it was thought 

 worth while to bear it in mind, and to investigate the matter 

 further. ^ 



In 1888 I again visited Waterville, but owing to delays did 

 not reach there till July 2r)th, at which time the lakes had become 

 quite clear of the sus])ected algte. I. found that U\o calves had 

 died at Waterville on June 4th, and about the same time five cows 

 at Cordova, twelve miles distant, on Lake Gorman. The most care- 

 ful examination into the circumstances attending these cases threw 

 no additional light on the subject. 1 arranged, however, to receive 

 a prompt notice the next season, should any more cattle die in the 

 same manner. 



The^middle of June, 188A, word was received that eight cat- 

 tle had died on the shore of Lake 'JVtonka. I at once started for 

 Waterville, arriving o/i the twentieth and found the algie less 

 abundant than in 1882, but still making the water green some 

 fifty feet or more out from the shore toward which the wind had 

 been blowing several hours. Although the conditions were not 

 the most favorable, yet it seemed best to attempt a direct experi- 

 ment by giving animals water charged with the a]ga\ After much 

 delay the services of Prof. M. Stalker, state veterinarian of Iowa 

 and professor of veterinary science in thelowa Agricultural College, 

 were secured to conduct the experiment. A horse and calf were 

 employed. On June fiOth, Prof. Stalker, with the assistance of 

 Prof. Edward D. Porter of the university of Minnesota, and in 

 the presence of citizens of Waterville, made the tests, the writer 

 being unable to remain. The animals had not been permitted to 

 drink for some twentj^-four hours previous, and were consequently 

 thirsty enough to take a large amount of water well charged with 

 the alga?. No^bad results of any sort followed. 



