ON SERICICULTURE. 149 



ation on all important points, ought to induce a re-consiclera- 

 tion of the question not merely of cultivating the B. Mori 

 in our colonies, but also of fairly testing the experiment of 

 its culture in Great Britain. 



I would advance a favourite theory of mine as bearing 

 on this point. In consequence of improvements in agricul- 

 ture, our land is much better drained of late years than 

 formerly, a great number of woods, trees, hedge-i'ows, &c., 

 have been cleared away ; hence I believe two changes have 

 taken place: we have less rainfall than formerly;* the soil 

 and atmosphere generally are drier, and our average tem- 

 perature has somewhat increased in the months in which 

 silk-worm culture is carried on — May, June and July ; the 

 first of these changes is the most important to Sericiculture, 

 as moisture is fatal to the mulberry worms ; the second is less 

 so, as the temperature of a Magnaniere can always be elevated 

 by artificial warmth. 



If these changes have taken place, our climate has then 

 become more decidedly favourable to mulberry silk culture, 

 and I can well understand that with the advantages of in- 

 creased information, swift communication and interchange of 

 ideas between distant countries, a warmer and drier climate, 

 a tree better adapted to the culture of the worm, and with 

 healthy seed obtained from distant silk-growing countries, 

 the experiments of mulberry silk culture, which failed in 

 1825, may now be repeated with success. 



My Japanese correspondent writes, October 2nd : — "This 

 season has been unusually bad this year for silk-worm eggs, 

 and the quantity is 500,000 cards, against 1,500,000 last 



* If not actually less in quantity, I am convinced there are fewer 

 rainy, damp days, and that one peculiarity in our summer seasons is that 

 the rain, when it comes, falls heavier but is sooner over than formerly, 

 and is more quickly carried off the land into the sea. 



