EXPERIMENTS IN HYBRIDIZATION AND TEMPERATURE. 345 



No. 122 (PI. III. figs. 4 and 5) ; No. IS^ (PI. VI. VII. VIII ; 

 also Exper. zool. Studien, 1898, PI. V. fig. 6). 



But moreover all three Saturnia species were combined for 

 making up a hybrid— the male hybrid from the crossirig of 

 S. pavonia <? X s])ini ? —that, is. No. 8 being crossed with a 

 female of the third species. No. 14^ (PL IV. figs. 1 and 2 ; also 

 Exper. zool. Studien, 1898, PI. V. figs. 7, 8, 9). 



Even still more complicated hybrids were bred to the imago 

 stage. No. 18^ (PI. IV. fig. 3), and No. 19^ (PI. IV. fig. 4) ; 

 whereas from the hybrid crossings Nos. 15, 16, 17 only larvaB 

 were obtained, which, though in part nearly full-grown, died of 

 an infectious disease. 



When large Dalmatian S. pavonia females (received from Zara through 

 Spada) were used for this experiment instead of the much smaller Ziirich 

 form, the resulting hybrids measured— the males from 83 to 95 mm., gynan- 

 dromorphic and females from 84 to 97 mm. 



2 The hybrid figured (PL III. figs. 4 and 5) resembles S. spini in struc- 

 ture and coloration. The male differs from 8. spini, however, in the smgle 

 coloured dark grey-brown hairs of the upper side of the abdomen, while the 

 female possesses the broken transverse band at the base of the fore wings, 

 which is a peculiarity of S. pavonia. 



3 The secondary hybrids (PL III. figs. 6, 7, 8) are also of one brood, from 

 a strong hybrid male of No. 8 and a large Dalmatian 8. pavonia $ . Of this 

 form (which I have named after the esteemed editor of our paper, Herrn 

 Director, C. Schaufuss, 8. hybr. schaufussi), two males (figs. 6 and 7) and a 

 gynandromorphic specimen (No. 8) are figured. i • i, t 



* Of this highly interesting secondary hybrid of three species, which I 

 have named S. hybr. schlumbergeri, in honour of Herrn Staatsrath Dr. J. 

 von Schlumberger, of Gebweiler, a pair is figured (PL IV. figs. 1 and 2). The 

 female gives one the impression of a very large gigantic 8. spini. The male 

 also inchnes mostly to a large male of this type, without, however, entirely 

 discarding its connection with 8. pavonia and p2jri. Two male pupae of this 

 rarity have already gone over three winters without developing, and wiU 

 probably go through a fourth without emerging. 



5 I succeeded in rearing two males of the same brood of this crossmg, 

 the only pairing between true hybrid forms that I have yet obtained. One 

 of these is shown (PL IV. fig. 3), and gives a very curious impression. At 

 first sight it appears to be an old well-known form, and the next moment an 

 entire stranger. The creature seems familiar when we simply regard the 

 coloration, which first forces itself upon one's attention, as it agrees so entirely 

 with a lightly coloured 8. pavonia female that it could easily be mistaken for 

 such. But the creature gives us quite a different idea when we notice that it 

 is without doubt a well-developed male. In fact, this creature agrees entirely 

 in structure with that of a 8. pavonia male, but possesses the exact coloration 

 of 8. pavonia female. 



By this crossing experiment the bright phylogenetically younger male 

 coloration is thrown back to the phylogenetic older less brightly coloured 

 female type. The second male is similar to this male in structure and size, 

 but on the upper side, on the outer border of the hind wings, and in the centre 

 of the fore wings, beneath the eye-spot towards the hind border, it possesses 

 numerous rosy scales, and resembles the rare somewhat red type of 8. pavonia 

 female. 



6 Of this also very compUcated hybrid, three males of the same brood 

 were successfully reared. The largest is figured (PL IV. fig. 4) ; the others 

 measure respectively 71 mm. and 73 mm. The mother and grandmother of 



