IS'4 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Dr. Trimble, after citing " Kirby and Spence" to prove his 

 former assertion that certain plants could not mature seed with- 

 out the instrumentality of .certain insects in their fertilization, 

 stated that he had examined these insects a month ago and found 

 them to be the aphis, or plant-louse. He had found upon inves- 

 tigation that it has been attacked by a parasite insect -which 

 would keep it in check. The aphis is remarkable in its rate of 

 increase. It commences early in the spring, and there are eight 

 successive generations during the summer. Then comes a genera- 

 tion of winged insects, which lay eggs to produce the young for 

 the next summer. It has attacked vegetation generally this 

 summer. The wheat-fields and oat-fields are black with them. 

 Yet he should not apprehend any material injury to the grain. 



Mr. Carpenter did not consider the appearance of this insect 

 an occasion for alarm. Grain does not appear to be injured in 

 the least by them. They might injure tender shrubs. 



Mr. Bergen had had his cucumbers so much injured by them 

 that he would obtain but $50 from a plot which usually yielded 

 $250. He should be compelled to abandon the raising of cucum- 

 bers on this account. They have injured squash plants, but not 

 to such an extent. "Watermelons are much injured by them. 



Mr. Fuller regarded the aphis as an insect doing great injury. 

 If he did not destroy them upon the grape vines early in the 

 season, they would injure them so much as to stop their growth. 

 He had lately found that his strawberry plants had been attacked 

 by a sort of subterranean aphis. He was obliged to take up the 

 plants and clean them from the roots, and transplant to prevent 

 them from destroying his vines. Yet, there were none upon the 

 top of the plant. As to the fertilization of plants, although 

 there are works which throw out the hint that insects are indis- 

 pensable, he was not convinced of it. 



BUTTER-MAKING. 



Mr. Robinson read a letter from Clinton county inquiring why 

 the writer sometimes failed to obtain butter in churning, and giv- 

 ing in detail the facts respecting his cows, dairy, churn, &c. He 

 remarked that he had had the same experience this season, the but- 

 ter sometimes coming promptly, and at other times not for hours. 



Mr. Carpenter recommended the use of the thermometer churn. 



Mr. Robinson stated that the writer used the thermometer in 

 churning, and the cream was brought to the temperature of 62 



