THE AMERICAN ENTOMOLOGIST. 



same fact in comparing butterflies from 

 those parts of British North America, where 

 the species may be presumed to be mono- 

 goneutic, with the same species from Mis- 

 souri, where it is digoneutic. This gen- 

 eralization does not apply to species that 

 hibernate in the imago state, though even 

 here the lower mean temperature of the 

 sub-boreal zone lessens the average size 

 and renders the colors less strong. This 

 is not noticeable with species like Daiiais 

 archippus, which, we believe, annually mi- 

 grate to such sub-boreal regions from more 

 southern points. Mr. Edwards's experi- 

 ments indicate that artificial cold on the 

 chrysalis produces in' the resulting imago 

 the same effect that cold does in nature. 

 We quote his general conclusions : 



1. Papilio ajax. The longer the exposure 

 under a low temperature the more decided the 

 change, but 25 or 30 days seem quite sufficient in 

 many cases, and changes have been produced by 

 exposure for 20, 16 and 11 days ; no changes re- 

 corded at less than 11 days ; while exposure at 8 

 days and less has produced no effect in some 

 cases to prolong the chrysalis period. 



2. The longest interval between pupation and 

 exposure to cold when any change has resulted, 

 has been 3 days. In all instances beyond that no 

 change has been produced. The shortest inter- 

 val has been two hours, and in this instance the 

 buttertly was changed to ivalshii, which is a 

 change more extreme than to telamoiiides. Most 

 chrysalids exposed so early die in the process, 

 but as many changes have been effected when the 

 age of the chrysalis at exposure has been from 12 

 to 24 hours, I believe that to be the most satis- 

 factor\- period. The chrysalis has then become 

 hardened, and the growth of the organs of the 

 pupa probably then begins, and their direction 

 may best be turned by the cold then applied. 



3. The effect of the cold is to albinize the 

 butterfly, the black area being constantly reduced. 



4. Cold has failed to change the shape of the 

 wings, its influence being confined to coloration 

 and markings ; the frontal hairs of the head have 

 also been changed ; and the sexes are equally 

 susceptible. 



5. Grapta interrogation! s. 14 days' exposure 

 after the chrysalids have hardened, has been 

 found sufficient to produce changes ; and the 

 females were most susceptible to the influence of 

 cold. 



6. With different species the degree of temper- 

 ature required to produce the most decided change 

 varies. I have succeeded best with FJivciodes 

 tharos, at 40'^ F. [4.4' C.]. At 32° F. \o° C] have 

 destroyed many Grapta chrysalids, but this may 

 have been principally because the chrysalis was 

 too tender when exposed. ' With P. ajax 32" to 

 40° F. [o'^ to 4.4° C] seems a proper temperature. 



M}- experiments with Ph. tharos are given in 

 Can. Entom., v. IX, p. 4, and p. 204-206. Also 

 in Butterflies of N. A., v. II, pt. 7. In the former, 

 a complete change was brought .about, and ever}- 

 butterfly emerged in the winter form. Temper- 



ature about 40" F. [4.4" C], and continued for 

 7 days, the chrysalids being 3," 6, g hours old 

 when exposed, and before several had hardened. 

 In the second experiment the temperature was 

 about 32° F. [o' C] ; the chrysalids were 10 min- 

 utes to g hours old, and the exposure was about 

 20 days. It was found that the butterflies emerg- 

 ing from chrj-salids which had been from i to g 

 hours old were completely changed ; some which 

 had been from 30 to 60 minutes old were not 

 changed, while others of same lot were greatly 

 suffused. I concluded that with this species it 

 was not necessary that cold should be applied 

 after the chrysalids had hardened, in order to 

 change the form. 



THE ROMANCE OP A CATERPILLAR. 



BY \VM. C. 



Of the insect tribes the most directly 

 useful to man have been the producers of 

 honey, silk and cochineal. The importance 

 of the Bee to the ancients will be realized 

 when we consider that they had to rely on 

 honey alone for the means of sweetening 

 food. Plato and Sophocles were honored 

 by being called respectively the " Athenian 

 Bee" and the "Attic Bee," in allusion to 

 the dulcet style of their writings. The 

 great attraction of the land which the 

 Children of Israel struggled so hard to at- 

 tain, was due to its reputation of flowing 

 with milk and honey. In the paradise 

 imagined by Lucian, honey spouted from 

 some of the fountains. Sugar was then 

 little known, except as one of the rare and 

 curious things from the far East, and 

 Strabo probably refers to it in a descrip- 

 tion of certain stones that had the color of 

 frankincense, and a sweetness greater than 

 that of figs or honey ; they were obtained 

 in India. Pliny is more precise ; he says, 

 " Arabia produces sugar, but that of India 

 is preferable. It is a kind of honey, col- 

 lected within reeds — a gum, almost white, 

 brittle to the teeth, the largest (pieces) of 

 the size of a hazel-nut, used only in medi- 

 cine." Let us imagine for a moment that 

 sugar should become equally rare at the 

 present time. Would not the sweetness of 

 life seem to have departed ? In the region 

 beyond the Ister, according to the story 

 told to Herodotus, the land was so com- 

 pletely possessed by bees that travel was 



* Read before the Linnean Society of New York, January 

 •i4th. 1880. 



