THE ENTOMOLOGIST. 
Vou. XXV.] JUNH, 1892. [No. 849. 
COLOUR-VARIATION IN THE OVA OF BISTON HIRTARIA. 
By Rosert Apxin, F.E.S. 
On 29th April, last year, I took a fairly fresh female Biston 
hirtaria at rest on a wall near here, and being desirous of rearing 
the species from ova, I put her aside in a large chip-box covered 
with leno; and upon examination, after two or three days, I found 
that she had deposited a considerable number of ova in cracks in 
the box; these were then of the colour that I have been accus- 
tomed to regard as natural to this species, a deep green. During 
the next day or two further ova were deposited; these were, at 
first, a pale golden yellow, but afterwards turned to a deep 
orange, which colour they retained; and a few that were 
deposited still later remained of the pale colour, without showing 
“any perceptible change. On the 30th of the same month I took 
a much worn female from the bole of a lime tree, and, as she 
showed some variation from the one previously taken, I kept 
her, also, for ova; evidently the bulk had already been parted 
with, but of those that I obtained, which were at first all of the 
pale golden yellow colour, the earliest deposited changed to a 
yellowish green, the next to a pale orange, and the latest 
remained yellow, as in the former case. I concluded that those 
that had not changed colour would prove infertile, but with a 
view to satisfying myself on this point, [ carefully divided the 
proceeds of each moth into three lot8—marked resnectively, 
MondkawA 57 Not: 1. Bs Now? Gi condeNose. A. No. 2... Bs 
No. 2. C,—according to the order in which the ova were 
deposited. In due time each lot became almost black, and 
subsequently hatched, but not in the order in which they had 
been laid, as will be seen by the following table :— 
No. 1. A. Turned colour, June 2; hatched, June 3. 
15% a »  vune 8; s: June 10. 
C. is ‘4 June 4; 3 June 5. 
ENTOM.—JUNE, 1892. 9) 
