THE TECHNOLOGIST. [Nov. 1, 1864. 



182 ON THE REVERSION AND 



Europe, and proceeds from weakness in the glands attached to the 

 ovipositor, and which do not, in consequence, secrete the gum necessary 

 to attach the egg. A few will of course always be found to adhere at 

 first, but so slightly, that the least touch causes them to fall. 



In the spring of 1863 the eggs obtained in the previous year from the 

 dark stock began to hatch on the 16th of March, and no sign of disease 

 was apparent among them until the moths came forth from the cocoons, 

 when many of these still showed defect in the malformation and dark 

 spotting of the wings. As compared, however, with the previous year, 

 there was decided improvement ; there were still too many white 

 worms in the brood, but they did not show any symptoms of disease 

 and none died ; they attained to a larger size by a quarter of an inch, 

 increasing from three to three and a quarter inches in length ; they pro- 

 duced, in consequence, larger cocoons, though still deficient in silk, and 

 the moths, although still showing the presence of disease, laid good-sized 

 eggs, great numbers of which adhered firmly to the paper upon which 

 they were deposited, and indeed one sheet of paper was thickly covered 

 with them — a thing which, although I have paid attention to this sub- 

 ject for the last twenty -live years, I never witnessed before, nor even 

 heard of it. The eggs of other species will adhere, but to find those of 

 the Bombyx mori doing so is truly a novelty which betokens decided 

 progress towards a healthier condition. 



There was likewise another indication of returning strength to be 

 seen in the fact that, while ordinarily the male moths are so sluggish as 

 to make no attempt to fly, many of those produced from my black stock 

 left the trays and flew off to seek the females in a distaut part of the 

 room. This is one of the marked characteristics of the wild moth Bom- 

 hyx Huttoni, which flies off from tree to tree for long distances when 

 " on amorous thoughts intent." 



But still more extraordinary appears the fact that some of the eggs of 

 B. mori of the spring crop of 1863 began to hatch again for a second 

 crop on the 7th of August of the same year : these were all from the 

 dark stock, and the circumstance, in itself perfectly novel, arises, I am 

 inclined to think, from an accession of strength acquired by reversion to 

 a state approaching more nearly to the original constitution. 



The hatching continued throughout August, and occasionally even 

 to the 23rd of September, when, fearing that my supply of leaves might 

 fail, the eggs were removed to a temperature below 70 u Fahrenheit in 

 order to check the hatching. 



The worms now hatched continued to grow and thrive, and spun 

 good cocoons superior in size to those of the spring crop, the worms 

 attaining to 3yV inches in length. In due time the moths appeared and 

 were fully twice as large as those of spring, depositing large well-formed 

 eggs. In the beginning of December, to my dismay, more worms were 

 hatched from the spring batch, and continued to come forth throughout 

 the month at the rate of forty or fifty daily in a temperature of 53° 



