Ae ee Se 
Entomological Society. 9089 
and produced larger cocoons, and the moths laid good-sized eggs, great numbers of 
which adhered firmly to the paper upon which they were deposited, and many of the 
male moths displayed unusual vigour in flying in search of the females. But still 
more extraordinary was the fact that some of the eggs of Bombyx Mori of the spring 
crop of 1863 began to hatch again for a second crop on the 7th of August; these were 
all of the dark stock. The hatching continued throughout August, and oceasionally 
even to the 23rd of September, when, through fear that the supply of leaves might fail, 
the eggs were removed to a temperature below 70° Fahr., in order to check the 
hatching. The worms which were then hatched throve and spun good cocoons, 
superior in size to those of the spring crop; in due time the moths appeared and were 
fully twice as large as those of the spring, depositing large well-formed eggs. In the 
beginning of December, to the author's dismay, more worms were hatched from the 
spring batch, and they continued to come forth at the rate of forty or fifty daily in a 
temperature of 53° Fahr., until, there being no more leaves upon the trees, the 
remaining eggs were placed in the open air at night, in order that the hoar frost 
might put a stop to further hatching. The whole of these worms were of the dark 
kind, and no white ones appeared amongst them as in the spring. This circumstance, 
so unusual with Bombyx Mori, the author attributed entirely to an accession of 
health and strength in the black worms; he regarded the occasional occurrence of the 
dark form in domestication as an attempted return on the part of Nature to the 
original colours and characteristics of the species, and considered the whiteuess of the 
generality of the worms as a positive indication and proof of the destruction of the 
original constitution; in fact, the dark worms were the original and natural worms, 
This conclusion was further supported by arguments deduced from the strong 
similarity in the disposition and arrangement of the markings to those of the existing 
wild races in India, and by analogy to the general fading in domestic stocks of the 
original colour, to give place to piebald and finally to white. The author had long 
entertained the idea that the production of white cocoons (except in those cases 
where the white was permanent and constant in all climates) was a strong sign 
of degeneracy, the white cocoons being more abundant where the temperature 
was high than in more temperate climes; the whiteness of the worms and the 
white cocoons were both indications of failing constitution, evidencing the existence 
_of a higher temperature and more artificial treatment than was conducive to the 
health of the insect. The author proceeded to argue that the good quality of the 
silk produced was no proof of the general health of the insect; it was the quantity, 
rather than the quality, of the silk that was affected by the present maladies; 
too great fineness of the silk was, in fact, an indication of too high a temperature, and 
of the consequent degeneracy of the worm. After considering at some length the 
question “ What species of mulberry-tree is best adapted for the nourishment of the 
silkworm and for the production of good silk ?” the author concluded by recommending 
the sericullurist to separate his dark worms from his general stock, to set them apart 
for breeding from, and to annually weed out all the pale-coloured worms; in the 
course of three or four years he would be able to cast aside his present sickly stock, 
and would have a stock far healthier than had ever befure been seen in Europe.— 
‘J. W. D. 
VOL. XXII. 264 
