v-^ 



0Qq^ philosophical transactions. [anno 169/. 



stone therein, they were soon killed by its fume; and 3 hours after putting 

 some more moths into the vessel, the scent that remained therein killed them ; 

 from hence guessing at what might serve for a larger room, I took for a granary 

 24 feet long, and 16 broad, -J- of a pound of such brimstone, prepared so as 

 wine-coopers use to do for their casks, which I placed in the midst of the room, 

 and setting it on fire, left it, shutting the door, and after two days I came 

 again, and found some moths alive on the wall, but not a tenth of what used 

 to be there, and which I judged might get into the room through the broken 

 glass of the window, or they might have crept out of the aurelia after the 

 smoke was over ; wherefore the best way is to smoke the room as soon as the 

 moth appears, and that for some days successively, which is but a small charge. 

 And in autumn it would do well to sweep the worms off the walls, for being a 

 tender insect, they are easily killed. 



At the time of the woh's creeping up the walls, I saw many small animalcules 

 of the size of a great sand on the walls also ; they had their hinder part broad 

 and short like a louse, and four horns. These animalcules laid small eggs, in 

 shape almost of a lemon : they were not long-lived, possibly for want of their 

 proper food, for some of them had eaten others for hunger: these eggs were 

 ' hatched in May, and the young ones were of the same shape with their parents, 

 so that these insects produce their like, as do lice, mites, fleas, &c. 



In ■ rain-water I observed a small red worm, and two other kinds of very 

 minute insects; of those of the larger size I judged that 30,000 together would 

 not equal a coarse sand. These I observed for several days, and saw them co- 

 pulate, the larger dragging the smaller through the water after them, swimming 

 by means of very small fins. I saw likewise another sort of smaller insects in 

 the water coupled, 20 times more in number than the former. 



As to insects bred in apples, I observe that in the spring, when the trees 

 begin to bud, a certain black fly lights on the blossoms, and lays its eggs there. 

 This insect flies from one bud to another, and I doubt not but if we observe 

 these black flies, and the caterpillars which soon follow them, we should find 

 that the caterpillars generated by black flies, change to black flies again. 



About two years since I put some cheese-maggots* in a glass tube in my 

 pocket, and at last found the maggot turned to a red aurelia from pure white ; 

 and these again changed into a black fly ; which experiment I often renewed with 

 the same success, though I could not keep these flies till they laid eggs, it 

 may be for want of convenient food. From these and several other observa- 

 tions, I conclude there is no generation but from the parent animal. 



* These maggots are the larvae of the musca putris, Lin. 



