OBSERVATIONS ON BLIGHT. 365 



yet there were some beetles from the very first coming up of 

 the plant: now I knew from experience, that the turnip- 

 beetle fed on wild mustard and several other hedge plants, 

 and therefore it was not at all an improbable thing, that when 

 they smelt the fragrance of the fresh bursting cotyledons of 

 their favourite food that they should skip down from their 

 spring habitations, the hedges, and commence the attack. 

 This would account for the few beetles observable from the 

 first, but not for the numberless grubs which covered the 

 cotyledons, riddling them with holes, and devouring the 

 succulent stems, even that part which was covered by the 

 ground. These must have sprung from eggs either left in the 

 ground last year or have been laid on the turnip-seed itself 

 and harvested with it in the autumn. 



I first sowed some seed in a flower-pot with earth out of my 

 garden ; it produced the animal in abundance. Secondly, I 

 inclosed the pot with pasteboard and canvas with the same 

 success ; but there was still a possibility of the enemy getting 

 in, as I had not made the cover sufficiently close. Thirdly, I 

 made a light frame, about eight inches square, covering it with 

 very fine silk gauze, and carefully stopping the crevices of the 

 door with pasted paper, and round the pot, where the cover 

 was fastened on to it with putty, so that there was now no 

 possibility of any thing coming to it from without ; yet this 

 experiment was attended with the same success : however, one 

 point, that is, a negative point, was now proved, namely, that 

 the fly did not come to the tui-nip from other plants ; this 

 was a point gained. Fourthly, I baked the earth in a cast-iron 

 pot over the fire, and used no water to water the seed but such 

 as I had boiled myself, applying it at the bottom of the pot in a 

 common feeder, then I used the same care and took the same 

 precautions as before — I did not take oflT the cover till the plants 

 were of a considerable size, and I found them all a-hop with 

 beetles. I had now made another step; that the beetle did 

 not come from other plants, I had found before ; but now it was 

 clear that it was not in the earth nor in the water. Fifthly, 

 with a lens I examined the seed, and found on it a number of 

 white flattish substances, some seeds were without any, but 

 there were generally one, two, three, four, and in one instance 

 five, on a single seed; these I concluded to be eggs, and 

 thought the only way now left me was to attack them ; it would 



