ARASCHNIA. 



189 



I continued my researches with activity, and soon succeeded in collecting about forty of these little groups, amounting 

 altogether to more than six hundred eggs, which hatched between the thirtieth of July and the fifth of August. Of 

 nearly six hundred larvas, little less than four hundred reached their full growth. I saw no difference in them, except 

 that some had the spines yellow instead of black. When they had become pupae I examined them with the greatest 

 care, without discovering any differences. I expected to rear Prorsa, which I had never yet bred. As to Levana, I 

 had reared about thirty from larva?, which were full grown in the beginning of September. As I had only seen Prorsa 

 where I found the eggs, I could expect no other insect. From the second till the ninth of September, about forty 

 butterflies appeared, all Prorsa ; then, on the eighteenth of October two more butterflies, partly Prorsa, partly 

 Levana, the variety indicated in the Mazzola and other older collections under the name of Porima. This 

 circumstance at once awakened all my attention. Every clay I visited my pupaj, but no more butterflies appeared. 

 Those which had not yet hatched, by far the greater portion, remained during the first winter month exposed to intense 

 cold. In the beginning of February I removed some of them to a heated room ; and to my surprise, in about six days, 

 there came forth Levana only. From the middle of February till the beginning of March I did the same successively 

 with the rest of the pupa;, and from about three hundred I obtained Levana only ; there was not one Prorsa." 



It is quite clear from these facts that the insects known by the name of Levana are but the vernal variety of those 

 which have received the name of Prorsa ; that the variety known by the name Porima is an intermediate variety, 

 appearing at an intermediate period of the year, and moreover, we are told, capable of being produced at pleasure by 

 removing the pupae into a warm room in November or December. The natural inference is, that the change of colour 

 is produced by exposure to cold : but why do the pupce exposed to a longer cold produce, in July, only Prorsa ? Is this 

 the fact ? It may be well to reject this part of the history, until we have further evidence. 



But Geyer's statements by no means support what are certainly Duponchel's, and apparently his own, views. He does 

 not get Levana from the egg of Prorsa, and Prorsa from the egg of Levana ; but he raises Prorsa, Porima, and Levana 

 from the same batch of eggs. And here arise several questions. What becomes of the eggs of these different 

 varieties ? Does Porima lay eggs ? or are the females always sterile, as is often the case with the great majority of 

 females of many species of Lepidoptera? What becomes of the eggs of the females of Prorsa which appear in 

 September ? Perhaps it was from the eggs of this brood that Geyer had formerly reared Levana. Has any one reared 

 specimens from the eggs of Levana, or found larvae in the spring which have produced Prorsa in Julv ? All these 

 points want elucidation, and I cannot find any observations tending to this. Our cautious, close-observing, pains- 

 taking fellow-labourers in Germany will, I trust, some day be able to give us all the needed information on these 

 interesting points. That the colour of Lepidoptera sometimes is influenced by the length of time passed in the pupa 

 state is well known, especially in the ease of Chariclea Delphinii. This beautiful moth passes one, two, or even three 

 winters in the pupa; and the richness and deepness of colouring of the perfect insect are in proportion to the time passed 

 in the pupa state : hence, many Continental Lepidopterists do not preserve the specimens which appear the first or 

 second year, but await those of the third, which are so much more beautiful. 



The Larv^, are subcylindric, tapering towards the head, each segment, except the second and last, armed with two 

 branched spines, those on the head the longest. The most common colouring is dark olivaceous, with the lower surface 

 pale ; sometimes the sides have interrupted, longitudinal, pale bands. They live in societies of about a score, on the 

 common nettle, preferring generally the moist parts of woods, or shady spots in fields. 



The Pup^; are tuberculate, with the head deeply bifid. 



The Geographical Range of this genus appears not to extend beyond the middle zone of Europe. 



ARASCHNIA. 



A. Prorsa Hufm. Verz. '«■/,-. Schmett. 37. (1816). 



Doubleday 3$ Hewtson, t. 26. f. 1, 2. (1848). 



I'. Pr. Lhi». Syet. Nat. 11. 783. n. 202. (17d'7). 



Fab Kid. Sijst. m . i. 256. 11. 795. (17.93). 



Hiibn. Eiirop. Schmett. Pup. f. 94-6. (1S06). 



Van. Pro. Godt. Enc. M. ix. 311. n. 34. (1S19). 



Var. Vem. P. Levana I, inn. Syst. Nat. 11. 783. 



n. 201. (1767). 



November, 1 848. 



Fab. Ent. Syst. 111. 1. 256. n. 794. (1793). 

 Iliihn. Europ. Schmett. Pap. f. 97-8. 1 4.j. 

 728 9. (180(J-27). 

 Ar. Le. Hubn. Verz. beh. Schmett. 37. (lSlfi). 

 Van. Lev. Godt. Em: M. ix. 312. n. 35. (1819). 

 France, Switzerland, Germany, Polish Ukraine, &c. 



B. M. 



3 E 



