24 Mr. J. W. Tutt on recent Experiments in 
and November Ist, 1897. These may be grouped as 
follows :— 
9f — These are small dull grey males with the 
ground-colour much suffused as in the pale 
males of crossing II. One is inclined to say 
that they have a slaty hue. The marks are 
ill-defined, since they merge into the darkish 
ground-colour. They resemble the second 
brood of 7’. bistortata in the absence of definite 
markings and general suffused appearance ; 
they approach 7’. crepuscularia in the squarer 
forewings. These emerged chiefly in June. 
3¢ Small; ground-colour strongly suffused with 
ochreous; transverse markings moderately 
distinct. 
28 gf Rather larger, and fuller winged than the pale 
specimens. Of the form with the ground- 
colour suffused with fuscous. These larger, 
darker and more strongly marked specimens 
were the last to emerge, chiefly in late Sep- 
tember and October; two as late as Octo- 
ber 30th and November 1st respectively. 
40% —® 5 pups going over on November 10th, 1897. 
The two last crosses enumerated represent the reciprocal 
crosses of typical 7. bistortata and 7. crepuscularia. The 
following points are noticeable. I. Cross with 7. bistortata 
as ¢ parent produced 47 per cent. females. The cross with 
T. crepuscularia as $ parent produced no females. II. In 
both crossings the earliest specimens to emerge were much 
the palest. These were females in the first case, males in 
the second. The ochreous specimens were those that were 
intermediate in the pupal state; the darkest, largest, most 
strongly marked and most vigorous-looking were much 
longer in the pupal stage. 
Mr. Bacot’s EXPERIMENTS. 
ORIGIN OF PARENTS USED FOR PAIRINGS.—These were 
from the same localities as those used by Dr. Riding, viz., 
Clevedon (Somerset) for 7. bistortata and York district for 
T. crepuscularia. 
