43 
others were afflicted with, and only 120 were found pupated when the 
pupae were removed from their cocoons, and during the months of 
November and December, 1901, and January, 1902,11 insects emerged 
from this batch of pupae, 4 of them being of the ab. nigra form, 2 of 
the type, and 5 cripples, all of whom were of the ab. nigra form; the 
rest emerged during May, 1902, and proved that when we get a pairing 
of a male and female of a distinct var. from the type, and ova laid, the 
product is almost certain to produce a preponderancy of that var. or 
ab., for from these 120 pupae, 76 were of the ab. nigra form, while 3 
only were of the type. There were also 17 cripples divided thus—14 
ab. nigra, and 3 of the type, while 24 of the pupae did not emerge; so 
that deducting these we find that out of 96 pupae, 90 insects were bred 
of the ab. nigra form, while 6 only were of the type, showing a 
percentage of just over 93%. The above statistics tabulated are as 
follows, and were given to the Society, when I made a large exhibition 
of bidentata on July 1st, 1902. 
Ova obtained 
from 
Number 
pupated 
Number 
ab. nigra bred 
Number 
type bred 
Cripples 
Did not 
emerge 
Typical parents .. 
77 
15 
25 
ab. nigra 
9 
type 
19 
9 
Ab. nigra 9 with 
typical S .... 
60 
21 
8 
4 
5 
22 
Ab. nigra S with 
typical ? .... 
57 
34 
9 
3 
1 
10 
Ab. nigra rf and 
?. 
120 
76 
3 
14 
3 
24 
314 
146 
45 
30 
28 
65 
During 1902 I obtained 11 pairings from ab. nigra parents, ab. 
nigra $ and typical 2 , nigra 2 and typical $ , and typical parents, 
and a goodly number of ova were laid, which likewise produced a fair 
number of larvte. These were chiefly fed on birch as I could not 
obtain ash in such quantities, but not many of this lot of larvae were to 
arrive at the pupal stage, for out of the whole lot only 20 pupated, 
which I find on closer examination have dwindled to 5, the other 15 
having died in the pupal state. No doubt the inbreeding was telling 
on them, and that the third generation was weaker than the preceding 
two generations, but I attribute the dying off of the larva3 this time, 
to them contracting a choleraic disease from some L. querciis which I 
was feeding, and which were dying off fast, and the cages being in 
close proximity to the cage in which they were feeding, the larvae 
hanging limp, flabby, and motionless from the twigs of birch, and in 
this way they died by hundreds. Such, therefore, is my own and my 
brother’s experience in breeding the ab. nigra form of bidentata, which 
I hope has proved interesting, inasmuch as it gave us pleasure in 
breeding them. 
