16. On June 12th, 1871, specimens of _Pieris Napi_, var. _Bryoniæ_, were captured on a mountain in the neighbourhood of Oberstorf (Allgäuer Alpen), and placed in a breeding-house, where they flew freely about the flowers; but although copulation did not take place, several females laid eggs on the ordinary garden cabbage. From these caterpillars were hatched, which at all stages of growth were exactly like those of the ordinary form of _Napi_. They throve well until shortly before pupation, when a fungoid epidemic decimated them, so that from 300 caterpillars only about 40 living pupæ were obtained. These also completely resembled the ordinary form of _Napi_, and showed the same polymorphism, some being beautifully green, others (the majority) straw yellow, and others yellowish grey. Only one butterfly emerged the same summer, a male, which, by the black dusting of the veins on the margin of the wings (upper side), could be with certainty recognized as var. _Bryoniæ_. The remaining pupæ hibernated in a heated room, and gave, from the end of January to the beginning of June, 10 males and 5 females, all with the characters of the var. _Bryoniæ_. They emerged:-- On the 22nd of January, 1 male. ” 26th ” 1 male. ” 3rd of February, 1 male. ” 4th ” 1 male. ” 5th ” 1 male. ” 7th ” 1 female. ” 9th ” 1 male. ” 24th ” 1 male. ” 4th of March, 1 female. ” 11th ” 1 male, 1 female. ” 6th of April, 1 female. ” 17th ” 1 male. ” 11th of May, 1 female. ” 3rd of June, 1 male. We here perceive that the tendency to accelerate development through the action of warmth is, in this case, also very different in different individuals. Of the 16 butterflies only 1 kept to the normal period of development from July 27th to June 3rd, fully ten months; all the others had this period abbreviated, 1 male to eleven days, 8 specimens to six months, 4 to seven months, 2 to eight months, and 1 to nine months. APPENDIX II. EXPERIMENTS WITH PAPILIO AJAX.[58]