20 Mr. J. W. Tutt on recent Experiments in 
rather suffused type form has complicated the colour 
difficulties in dealing with the hybrids, but has made them 
more interesting. 8 ¢ and 10 9. 
(4) 7. crepuscularia ab. delamerensis.—From York ova, 
bred between February 26th and April 27th, 1897. 
Blackish-grey in colour, deeply suffused but with irregular 
grey patches; the white antemarginal line not particularly 
strongly marked. 
The broods marked 1, 3 and 4 are those from which the 
parents of the hybrids were selected. 
RECIPROCAL CROSSINGS OBTAINED.—Fertile reciprocal 
crossings from 1, 3 and 4 broods (above), were obtained as 
follows :— 
1.—T. bistortata f x T. ab. delamerensis 2 .—a. Paired 
March 11th; ova deposited March 15th; hatched April 
26th—27th. 
2.—T. ab. delamerensis f x T. bistortata 2 .—a. Paired 
March 9th; ova deposited March 14th; hatched April 
18th-19th. 8. Paired March 9th; ova deposited March 
13th—14th; hatched April 18th—19th. 
3.—T. bistortata f x T. crepuscularia 2 .—a and 8. Two 
pairings on March 17th; ova deposited March 20th—22nd; 
hatched April 25th—27th. 
4.—T. crepuscularia $ x T. bistortata 2 .—a. Paired 
Merch 7th; ova deposited March 16th; hatched April 
21st-22nd. 8. Paired March 14th; ova deposited March 
20th; hatched April 22nd—28rd. 
Reciprocal crossings that failed were: (1) Z. ab. dela- 
merensis § x T.bistortata § , two pairings—February 28th 
and March 12th. (2) 7. erepuscularia g x T. bistortata ¢ , 
three pairings,—March 7th, March 10th, March 14th. 
Hysrips.—I. Hybrids between f T. bistortata (Clevedon) 
x % T.ab. delamerensis (York)—No. 1 above. One batch 
of eggs; hatched April 26th—27th ; 100 imagines examined ; 
emerged between June 12th—October 22nd, 1897. These 
may be roughly divided as follows :— 
Ja Ls? The males scarcely distinguishable from male 
T. lustortata of the second (summer) brood ; 
the females much whiter and suggesting 
strongly typical ? bistortata of this brood by 
the clearness of the transverse lines. 
