142 Messrs. Prout and Bacot. On Cross-breeding of [Jan. 8, 



but hardly dark ; about half tend toward the light side. F 5 are similar to 

 F 4 , but perhaps less variable, very few pure light ; might in the aggregate be 

 termed light-intermediates. F 6 , 36 specimens, are pretty variable, about 

 11 light (only with a stronger central shade than in the pure Hyeres strain) ; 

 1 or 2 others nearly as light, weaker-marked ; the rest intermediate to darkish, 

 nothing extremely dark. The darkest pair available was used for parentage 

 of F 8 . F 8 (4 J, 16 ? ) are rather large, variable, the average dark, could 

 perhaps be classified as 11 (3 <$ , 8 ? ) dark, 5 ( $ ) intermediate, 4 (1 S , 3 $ ) 

 light, though not quite pure, but there are very gentle gradations ; duplicate 

 pairings out of F 7 (labelled C viii (2) and G viii (3)) vary somewhat less, 

 G viii (2) (33 specimens) being intermediates, slightly variable in detail, and 

 C viii (3) all being possible London forms (i.e., dark), variable only in detail. 

 F 9 was obtained only from the second of the above (G viii (2)) ; the specimens 

 numbered 35, still intermediates, not unlike the parent brood. 



Brood e. — Continued to generation F w . F 3 consists of 7 only, inter- 

 mediates, apparently not variable. F 4 varies from almost extreme light to 

 almost extreme dark, but with intermediates which preclude any possibility 

 of splitting up into darks and lights. F 5 (16 only) is similar, but the 

 preponderating tendency is on the dark side, only one being really light with 

 strong lines of dots. F 6 , 29 specimens, is perhaps even more variable, 4 or 

 5 at least being pure dark, 6 or 7 at least pure light, others nearing both 

 extremes (especially the light side) and a few intermediate. F 7 (from light 

 ^ x dark ? ) showed quite moderate variation, most being rather uniform, 

 lightish intermediate, 2 or 3 (<J) darker, without being strikingly dark. 

 F 8 , 52 specimens, are very variable : about 12 pure dark, about 12 pure light 

 (only with well-expressed central shade), the rest grading through. F 9 was 

 bred in triplicate; brood c ix 0, 30 specimens, from intermediate parents, 

 are very uniform, all being possible Clapton forms (dark), only 2 or 3 a little 

 paler than would be normal for Clapton ; c ix sfc, 7 specimens, from lightish 

 parents with distinct dot-lines, follow the parents closely ; the remaining 

 brood (stock ?), 56 specimens, shows moderate variability, but mainly inter- 

 mediate, the few darks and the few lights hardly quite pure. Fi was nearly 

 a failure, but 5 specimens ex brood c ix are all dark, 6 ex c ix f all 

 lightish, reproducing their parents' facies. 



Brood E. — Only continued for two generations. The original pairing, ex 

 generation F 3 , was obtained in duplicate. 



(1) In generation F 4 55 specimens were reared, all intermediate, the 

 variation not considerable. In F 5 , 83 specimens, the variation is con- 

 siderably greater, ranging from darkish (not extreme) to specimens closely 

 approaching the pure light strain, though slightly less pure, with central 

 shade better indicated. 



