34 Mr. J. W. Tutt on recent Experiments in 
were examined ; 38 f and11 ¢. These emerged during 
September and October. Only 2 ? were present among 
the first 37 emergences and 9 among the last 12. These 
consisted of 31 pale and 18 dark specimens. 
Dt ae Considerable ochreous suffusion in ground- 
colour, otherwise these specimens have quite 
reverted to T. crepuscularia and are of normal 
size for that species. One is darker fuscous 
and tends rather to the bistortata facies. 
uae Larger (with exception of one specimen) 
than males of this brood ; well marked females 
of distinct 7. bistortata type, but with a sus- 
picion of the whiter ground-colour of 7’. eve- 
puscularia. [The important factor relating 
to these females is that these specimens 
were longest in pupa, and show a tendency 
to be larger, a common sexual difference in 
T. bistortata in nature, but not in 7’. crepus- 
cularia. | 
Gee 2-2 These are of the 7. ab. delamerensis form, 
and are practically inseparable from those of 
the ¢@ parent brood, except that they are 
more mottled with irregular patches of 
white. 
882 112 
With the exception of the 7 females separated from the 
others above, the remainder of this brood are, to all 
intents and purposes, 7. erepuscularia. Only one who 
had made a very special study of these could tell that the 
latter had been crossed with 7. bistortata. 
This completes my summary of the various broods that 
I have examined. The comparisons of the different 
crosses have been made with: (1) Typical 7. bistortata 
of the first and second broods, bred from Clevedon ova ; 
T. crepuscularia, and T. ab. delamerensis bred from York 
ova by Dr. Riding. (2) Three second-brood examples of 
T. crepuscularia (parents of York origm) bred by Mr. 
Bacot (only five individuals of this brood are positively 
known to have occurred in England). (8) Some 200 wild 
specimens (or specimens bred from wild parents) of 7’. 
bistortata and about 150 of 7. erepuscularia and 7. ab. 
