AMERICAN INSTITUTE. 57 



cocliineal insect, and the same sum for lac, produced by an insect of India 

 that punctures certain trees. The silkworm causes an annual circulation 

 of two hundred and twenty millions of dollars ; the honey bee a million ; 

 gall nuts, produced by an insect, a million ; cantharides, or Spanish fly, 

 two hundred thousand dollars. The eggs of silk worms are a commercial 

 commodity of considerable value ; twenty-three thousand five hundred eggs 

 weigh precisely a quarter of an ounce ; the worm produced by one of these 

 eggs lives fifty two days, and increases in weight ten thousand fold in thirty- 

 one days, and during the last twenty-five days of its existence cannot be 

 induced to eat anything. Seven hundred and forty pounds of leaves I 

 found would yield seventy-one pounds of cocoons, producing, if they all 

 yielded as the one measured, a thread thirty-seven millions four hundred 

 and eighty-eight thousand feet long, or seven thousand one hundred miles. 

 As there are one hundred thousand species of insects, and time will not 

 permit us to discuss them all, we may as well stop here. 



COMPARISON OF THE SEASON. 



Wm. Lawton, New Eochelle : I have a daily record of the flowering and 

 fruiting of the principal trees for 30 years past — the following is a mem- 

 orandum for a few years past. It is remarkable to see how regularly and 

 even the seasons come forth, and that the temperature is nearly the same ; 

 the variation in seasons comes principally from the moisture of difi"erent 

 years. The Mayduke cherry has one peculiarity — it brings forward a par- 

 tially second crop, it ripening some two weeks after the first set. This 

 cherry and the Black Eagle bloom at the same time, yet the Mayduke 

 ripens two weeks the earliest, and it is a most valuable fruit. The tree is 

 not so ornamental as some other kinds — the Black Tartarian and Black 

 Eagle in particular are valuable for ornamental trees, independent of 

 fruit. In regard to the seasons, as indicated by my cherry trees, the fol- 

 lowing is from my memorandum of the time of blooming : 1850, May 9 ; 

 '51, May 3 ; '52. May 11 ; '55, 12 ; '56, 8 ; '58, 1. In 1854, May 7, the 

 trees were in bloom when the weather came on so cold that asparagus froze 

 solid. There was a great deal of rain in the last weeks of April. The 

 variation in wet and dry seasons has more effect upon early spring vegeta- 

 tion than variations of heat and cold. Whether land is underdrained or 

 not makes a great difference in the season of flowers and fruit — the soil 

 that is well underdrained producing not only the most and bert fruit, but 

 it matures earlier. 



NATURAL LAWS FOR FLOWERS AND FRUIT. 



Thos. W. Field, Horticulturist, Brooklyn, gave the following points upon 

 the subject under this head as follows : Some of the laws which govern 

 the blossoming of fruit trees, are: 1. That flowers are fertile in propor- 

 tion to the size of the fruit. Nearly all the flowers of plants producing 

 small fruit of their kind are fertile or perfect in their sexual organs. Few 

 of the flowers of plants producing large fruit of their kind are fertile or 



