488 Dr. Wallace on some Variations 
left at a higher temperature than the rest; these both spun up en 
the same day and emerged on the same day, and being of diffe- 
rent sexes paired together. A month later one 2 emerged; the 
rest passed the winter in pupa. In 1864, June 4th, one $ 
emerged from the cocoons of a late brood obtained from eggs 
from Paris in the autumn of 1863; on the 10th, a 9; the 11th, a 
$; the 12th, a 9; the 13th, a 9; the 14th, a 9; the 15th, two 
@; the 16th, two 9; the 17th, two 9; the 18th, four out, some 
were males. It was not till the 11th July* that one ¢ and 
one @ of the first brood appeared. - In that autumn (Oct. 8th) a 
$ emerged from a cocoon spun in the summer in the open air; 
on the 15th, a ¢ and a @ emerged; onthe 20th,a 9; the 2Ist 
a 9; the 23rd, a S; the 26th, a 9, and so on. In 1865 a é 
emerged on the 22nd May, one out of some pupee which had been 
taken out of their cocoons and put to force; on the 23rd, a 2; 
the 29th, a @ ; the 30th, threes ; the 3lst,a ¢; and soon. The 
summer of 1865 was very warm, and so on the 20th August a 
2? emerged (the cocoon was spun July 15th, thirty-six days pre- 
viously) ; on the 21st, a 9; on the 24th, a $; on the 26th eight 
were out ; these had all been forced under glass at a high tempera- 
ture during the larval and pupal states, to obtain a second brood, 
and in consequence were of a medium size. Of the brood placed 
as larvee on trees in the open air, one ¢ emerged September 24th ; 
on the 26th, six emerged; on the 28th, six more emerged; and 
so on; but I have not noted when so many emerged whether 
the males or females preponderated. In 1866, as before stated, 
the first two emerged (both males) on May 30th, being stunted 
specimens of the second brood; on June Ist, two 9 emerged of 
the first brood; on the 2nd, two ¢; and about the 10th they 
began to burst out in quantities. In the autumn, November 7th 
and Sth, one ¢ emerged on each day; both these were medium- 
sized specimens. The emergence therefore of the ¢ first is as 
four to two. I may add, that invariably at the commencement of the 
burst the males largely preponderated in number over the females, 
while towards the end the reverse was the case. The conclusion, 
therefore, from these observations that I have come to is, that 
* The first brood were from eggs sent to me by Lady Dorothy Neville, and 
having been for several years acclimatized in England, had become accustomed 
to one generation annually, and were by far the largest insects; the Paris 
brood were accustomed to two or three generations annually, according to 
temperature, and produced a smaller insect. Hence it is not possible to com- 
pare these two races together, as their antecedents were widely different. 
