15th of August to the middle of September, but in the south- 

 east they were full-grown in June ; they were observed as far 

 north as Amiens, and in abundance at Epernay by M. Paris, 

 who had discovered some eggs already hatched in ISfJS: at 

 Gison, in the department of the Eure, M. Passy detected 35 

 feeding upon the Lesser Periwinkle, Vinca minor. No doubt 

 is entertained in France that the strong and continued south 

 winds in 1834< brought the perfect insects from Africa, which 

 being carried to the north, they there deposited their eggs, and 

 consequently the larvae became abundant the following year. 

 As this accords with an opinion I long ago expressed in ac- 

 counting for the irregular appearance of some of our rarest 

 Papiliones, I readily subscribe to it; nevertheless I think that 

 other causes may at the same time be in action : for instance, 

 favourable circumstances might have contributed to an ex- 

 cessive multiplication in their native soil, which I believe to 

 be the impulse that leads insects to migrate, by which two 

 fatal results are avoided, the destruction of the plants on which 

 they feed, and the consequent annihilation of their own spe- 

 cies. I suspect that the D. Nerii is found to the extreme east, 

 probably as far as China ; it is common in the North of Italy 

 even to Nice, and in 1819 the caterpillars were abundant in 

 the departments of the Maine and Loire. 



D. Nerii is undoubtedly closely allied to the true Sphinges, 

 and whether it be right to make a genus of it may be question- 

 able ; there are however several exotic species that will group 

 well with it: the caterpillar has a different character to Sphinx 

 (pi. 195), the spiral maxillae are very much shorter, and the 

 inferior wings are somewhat lobed, as in Deilephila. 



The caterpillar represented is from a highly-finished draw- 

 ing by Mrs. Tayleur of Teignmouth, which was transmitted 

 to me by Mr. Dale. It was found in Mrs. Mitchell's garden 

 in August 1832, and sent to Mrs. Tayleur, but the person 

 who took it handled it so roughly that it died in a few days. 

 The larvae, like the perfect insects, vary much in colour, and 

 I have never seen the figures of any that had more than a 

 double blue spot on each side of the thorax. The fine speci- 

 men of the Moth, which is a female, Mr. Leplastrier informed 

 me was taken by a poor man the latter end of September 1834, 

 near the pier at Dover, and was brought to him alive. Dr. 

 Bromfield states, in a letter to me from Southampton, " that 

 Ml'. Ingram, a nurseryman, took a fine specimen of S. Nerii 

 about four years ago, near Netley or Marchwood, in August 

 or September, and after having had it in his possession two 

 years, he gave it to Mr. N. M. Priaulx of this place, where I 

 saw it some time since." 



Vinca minor having been published in pi. 1 1 2, the Greater 

 Periwinkle, Vinca major, is now added to the Plate. 



