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Psyche 3:15-19, 1880.

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PSYCHE.
EXPERIMENTS UPON THE EFFECT OF COLD APPLIED TO CHRYS- ALIDS OF BUTTERFLIES.
BY WILLIAM HENRY EDWARDS, COALBCRGH, W. VA. (Continued from p. 6.)
With every experiment, however similar
the conditions seem to be, and are intended to be, there is a difference in results, and at present the reason therefor does not ap- pear. For example, in 1878, the first but- terfly emerged on 14th day after removal from the ice, the period being exactly what it is at its longest in this species in nature, with an occasional exception. Others
emerged at 19 days and several at inter- vals up to the 96th day after ice. In
1879, the emergence began at 8 days, and by 12 days all which came out this year
had appeared, except three belated indi- viduals at 22,40 and 50 days. In previous experiments, no matter what the species, the butterflies had not emerged till after the natural period of the chrysalis had
passed, after removal from the ice.
In
this one, either the cold had not fully sus- prided the changes which the pupa under- goes in the chrysalis, or these changes
were hastened by some other cause after
the chrysalids were taken from the ice.
In the first experiment, apparently, the changes were absolutely suspended as long as the cold remained.
It might be supposed that the application of hesit to the overwintering chrysalids would precipitate the appearance of the
summer form of P. ajax, or change the
butterflies so that while they had the shape of telammiides they should have the color- ation of marcellus. But I have not found this to occur. I have been in the habit, for several years, of placing the chrysalids in a warm room or in the greenhouse, early in the winter, so causing the butterflies to emerge in February, instead of in March
and April, as they would otherwise do. But the winter form has invariably emerged
from such chrysalids.
3.
In June 1879, I obtained eggs of
Grapta interrogationis, laid by form um- brosa. in confinen~ent. As the chrysalids formed, and at intervals of from 6 to 24 hours after pupation, they were placed in the ice box. After 14 days I removed all but five, which were left 6 days longer. Several were dead at the end of the 14
days. Temperature most of the time about 35O F. [1å¡. C.], but a little higher for a few hours each day, as the ice melted, reach- Pu&e 3 015-19 (prc.1903). hfp //psyche aitclub org/OT.OOIS htd



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16 PS YCHE.
ingtthen 40å to 45O F. [do to 7å C. 1.
I
broad band of the females), which occu-
obtained from the 14-day lot seven perfect pies the same position as the clouding in butterflies, 3 % 4 9 ; from the 20-day lot the normal male, but blackened and some- five, 4 '& 1 $ ; every one umbrosa; and
what diffused. In the four examples from nearly all had changed in one striking par- the 20-day tot, this connecting band ia ticular. In the normal umbrosa, of both
scarcely as deep colored and continuous
sexes, the fore wings on upper side have, as in the other three. Beyond this change on costal margin next inside the broad
on the submarginal area, whereby a con-
border
of hind margin, and separated spicuou~ band ia created where naturally from it by a considerable space of fulvoiia, would be only the two patches and a faint a dark patch which enda a little below the cloudiness over the intervening fulvous discoidal nervule ; inside the same border space, I see no difference between these at inner angle is a similar patch lying on examples of both sexes and a long series the submedian interspace. Between these
of natural oses placed beside them, so far two patches, across all the median inter- as relates to the upper surface.
spaces, the ground is fulvoua, but very
On the under side, all the males are of
slightly and faintly clouded with black. the same type, the colors intense. There is Indeed, this clouding would usually not be considerably more red, both dark and pale, noticed.
over the whole surface than in the series I find that in all the four 9 exposed to of natural examples ; these latter discovering cold 14 days, there is present a broad biack shades of brown, over which is a bluish or band crossing the entire wing, coatrinuous, lilaceom flush. In the females I discover uf uniform shade, covering the two patches no change on under side.
and intervening space, and almost confluent It appears that 14 days was as effective with the marginal border from end to end, in- producing changes in case of this @rap- only a streak of obscured fulvous any-
ta, as a longer period. In fact, the most where separating band and border. In
decided changes were found to be in the
the other female, being from chrysalis ex- females exposed least. It appears also that posed 20 days, the band is present, but cold will produce change if applied after while broad and covering the space between the chrysalis has hardened. In 1878, I the patches, it is not so dark aa in the other put Orapta chrysalids on ice at from 10 examples, and includes against the border minutes to 6 hours after pupation, and
ft series of obscured fulvous lunules.
This while some were quite soft, - and lost is like some normal females, and this fe -very one of them, although some chrysa- male, though longest exposed, therefore is lids of P. ujux in same box, and in part essentially unchanged.
exposed very shortly after pupation, were In all the males, the patches are diffuse, not injured, It also appears that cold may those at, apex almost coalescing with the change certain markings only, and that
border.
In the three males from the 14-
the females were moat susceptible to the day lot, these patches are connected by a influence. narrow dark band (very different from the The resulting butterflies were all wm-




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PS YCBE. 17
hsa, though both forma of the species age, remained in box 22 days ; three at might have been expected to appear. In 3 hours old, for 8 days, and one, age breeding from eggs laid by umbrosa in a omitted, for 6 days. All these produced
former year, I obtained both forms of the 'mar~eUvis, and therefore they had not been butterfly, viz. : 11 umirosa and 6 fabri- affected by the cold. cM. But from this siagle experiment it
cannot be determined whether any change 6. In 1877, I had placed several chrya-
of form was brought about.
alida of Lycaena pseudargiolus in the ice box, thinking that I might thus obtain the 4. In 1877, a, lot of eight chrysalids form vwlacea, which is the winter form of of P. ajax, all under 12 how from pupa-
the species. On 8 Aug., 31 days after the tion, were put on ice and left there 24 days. chrysdids were removed from the box, a (They were placed on top of the ice, but female emerged, in some respects consider- in all later experiments I have placed them ably unlike either of the forms- The m-
under it, iu the bottom of the box.)
The mon series of dark streaka and points across temperature was irregular, and as I was the disks was wholly wanting, though the absent from home nearly all of the time, stripes across the ends of cells were pres- and had to leave the box in charge of ser- ent ; and the marginal crescents were large vants, I felt no certainty that the ice had and black- far mure conspicuous than is not been supplied irregularly, or that there ever seen in the naturalpsettdarq~olu~, and A had not been intervals during which there still very unlike violaeea. The general was no ice in the box. But from these
coloration of both surfaces was that of the chrysalids there came 5 % 3 $ butterflies. usual fernalepseudargiolus.
All the other
Of these, one waa telamonides unqueatioa- chrysalids were found to be dead.
ably, in color and markings ; all the rest were between tehnwnides and maywUus.
In Can. Entom., v. 7, p. 236-240, I gave Two other chrysalids, on ice 23 days, in an account of the first experiments made the box at same time with the above men- by me in exposing chrysalids to cold, the tioned eight, gave telainonides. But three subject being P. ujaa;. The chrysalids more, exposed 26 days, and 1 hour from were placed iu the ice box, but were sub- pupation when placed in the box, all gave sequently removed to the ice house and unchanged mwrcelh~.
left, for two months after forming, but on In the box at same time were 6 chrysa- returning home after a long absence I lids of #. interrogationis, and all of them found the .ice had wholly melted. Tho
gave unchanged umbrosa.
chrysalids had at first been subjected to a low temperature in the box, but as the ice 5.
During the same season, 1877,I ex- in the house failed, the temperature had posed six J*. ajax chrysalids, keeping the risen so that when X examined the tin temperature as nearly as possible at 33OF. cases which had held the chrysalids, many [O.cO C. 1. One was 1 hour from pupation, butterflies were found alive therein in a and remained in the box 5 days ; one same crippled state. About one half the butter-




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18 P87CBJS.
flies .that emerged from thig lot were coin- partly or not at all ; from the 2Xay lot plctely changed, being teho'nides and all were changed. Temperature 33O + F.
wdlshii, and about half the rest were partly [0å¡. C,'}. charged. It was observed also that the
In 1877: chrysalids under 12 hours old,
butterflies were generally smaller than the bat the minimum not noted ; exposure 24 average mareeQus. I have not been able days. Temperature 40" F. [4A0 C.] and to subject chrysalids to cold for a very long upwards, irregular. Result : one changed
period, for the reason that ice fails us in fully, seven partly ; some others subjected midsummer, it having been put up when to same conditious for 23 days were fully thin and of poor quality, owing to our changed ; others at 26 days not at all. moderate winter climate.
Indeed, in aome In 1875 : chrysalids stated in my note seasons we get no ic~ at all, as the streams book to have been exposed as formed," do not freeze over.
On more than one but the exact age not given ; exposed for oecaaiou the period of exposure haa abruptly 80 to 60 days ; temperature at first about terminated, and much earlier than I had
8Z0 F. [0å C.], afterwards imcertah. Re- intended, by the failure of the ice. suit: 50 per cent. folly changed, 25 per cent. partly, rest not.
OF THE ISPEEIMENia WITH
GEHERAI, CONCLUSIONS :-
P. ujux*
1. P. ajax. The longer the exposure
In 1877 : chrysalids 1 to 3 hours old under a low temperature the more decided exposed from 2$ to 8 days.
Temperature the change, but 25 or 30 days seem quite 83O + F. t0.6' C.] . 'SO change effected. sufficient in many cases, and changes have In 1878: chrysalids 10 to 15 minutes been produced by exposure for 20, 16 and old, and at intervals up to 1 day, and then 11 days ; no changes recorded at leas than daily to 8th day from pupation ; expos- 11 days ; while exposure at 8 days and less ure from 19
to 5 days. Result : one
has produced no effect except in some cases telamonidea or walshii from chrysalis 12 to prolong the chrysalis period. hours old, 11 days exposure ; one walshii 2. The longest interval between pupa-
from chrysalis 2 hours old, 11 days expos- tion and exposure to cold when any change ure j one tela~mides from chrysalis 3 days has resulted, has been 3 days. In all in- - old, 16 days exposure ;
all the rest un- stances beyond that no change has been changed, but the periods of emergence
produced. The shortest interval has been remarkably prolonged.
Temperature 33O two houra, and in this instance the hut- + F- (0.60 C.].
terfly waa changed to wddtii, which is a In 1879 : chrysalids not less than 12 change more extreme than to teloi~~~~~ides. hours old nor over 24 houra ; exposed 14, Moat chrysalids exposed so early die in the 20, and 24 days.
Result: the period of process, but as many changes have been emerging greatly precipitated in nearly all effected when the age of the chrysalis at cases.
From the li-Swy lot there was no exposure has been from 12 to 24 hours, I change or only a partial one ; from the 20- believe that to be the most satisfactory pe- day tot, one half were changed, the rest riod. The chrysalis has then become hard-



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PS TOBE. 19
etted, and the growth of the organs of the With P. ajax 32O to 40" F. [0å to 4.4O C.] pupa probably then begins, and their direc- Beema a proper temperature. tion may best be turned by the cold then My experiments with Ph. tkaros are
applied.
given in Can. Entom., v. 9, p. 4, and p. 3. The effect of the cold is to dbinize
204-206. Also in Butterflies of N. A.,
the butterfly, the black area being con- v. 2, pt, 7. In the former, a complete itantly reduced.
change was brought about, and every bat- 4. Cold has failed to change the shape terfly emerged in the winter form. Temp- of the wings, its influence being confined erature about 40å F. [4.4O C-], and con- to coloration and markings ; the frontal tinued for 7 days, the chryaalids being 3, hairs of the head have also been changed ; 6, 9 hours old when exposed, and before and the sexe'a are equally susceptible. several had hardened. In the second ex- 5. Graph intewogatwnis, 14 days periment, the temperature was about 32" exposure after the chrysalida have hard- F. [P C.] ; the dirysalids were 10 mitt- ened, has been found sufficient to produce utes to 9 hours old, and the exposure was changes ; and the females were most BUS- about 20 days, It was found that the but- ceptible to the influence of cold, terflies emerging from chrydids which 6.
"With different species the degree of had been from 1 to 9 hours old were cop- temperature required to produce the most pletely changed; some which had "been decided change varies. I have succeeded from 30 to 60 minutea old were not best with Pftyciudes tharos, at 40å F. changed, while others of same lot were L4.P C.J. At 32' F. [06 C.] have de- greatly suffused. I concluded that with atroyed many G~apta chryaalids, but this this species it was not necessary that cold may have' been principally because the should be applied after the chrysalida had chrysalis was too tender when exposed, hardened, la order to change the form- REVIEWS.
PROFESSOR EDUARD BRANDT'S interest- the nervous system in more than fifty ape- ing papers upon the nervous system of in- ciea. Up to the time of appearance of
sects, which appeared during 1878 and
Professor Brandt's papers but little had 1879 [see Rec., noa. 1451-14581 in the been published upon this subject ; for ex- HOT& Societatis Entomohgicae 3f038iwe, ample, the metamorphoses of the nervona are valuable additions to the literature of system had been traced in only eight spe- the mbject.
The amount of research upon cies (four lepidoptera and four coleoptera) . which the author's conclusions are based, Many important facts were ascertained in can be beat understood, perhaps, by con- his studies, wad the papers, published both eidering that Professor Brandt examined in German and in Russian, and fully il- the nervous system of nearly a thousand luatrated with photolithographic plates, pre- species of adult insects, and of about one sent the facts in a systematic and carefully hundred and twenty-five species of larvae, condensed form. 0. D. and that he studied the metamorphoses of



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