POPULAR SCTEKCE NEWS. 



[June, 1889. 



find this fellow described in the books as Callidryas 

 enhule. 



Another very common species, the Jiinonia cnpnia, 

 has its wings olive-brown, with a dash of white 

 across the front ones, and two eye spots — a large 

 and a small one — on each wing. There is a reddish 

 bar on the lower part of the fore wings. One inter- 

 esting fact about this butterfly is, that the color of 

 the under surface of the wings, though it varies 

 considerably, is usually inconspicuous, so that, 

 when the insect alights, it is pretty well protected by- 

 its color. It is fond of darting about, and then 

 dropping suddenly down in the road, where it is 

 almost perfectly concealed by the blending of its 

 tints with the surroundings. 



The largest species we took was one of the 

 Papilios — those great fellows, with long tails on the 

 hind wings. No description can do them justice. 

 The ground color of the wings, which spread nearly 

 four inches, is dead-black. On the front ones is an 

 indistinct row of spots. If one looks at them in a 

 poor light, they are not attractive; but hold one in 

 the bright sunlight, and see what a change! The 

 whole hind wing flashes and gleams like polished 

 metal. Those of the male reflect a brilliant metallic 

 green, while the gleam of the wings of the female is 

 steel-blue. Across each runs a row of six or seven 

 white spots, contrasting sharply with the metallic 

 background. The under side is rather duller in 

 color, but the metallic sheen is still present, though 

 confined to .the outer half of each hind wing. In it 

 is a row of orange spots, bordered with white and 

 black. Even the mounted specimen fails to give a 

 clear idea of the brilliant eftect produced when a 

 dozen of these great beauties are seen hovering over 

 a bed of flowers, their wings flashing in the sun. 



Among the other prizes secured were several 

 ppecies of Argynnis. By far the most showy of 

 these is the A. (liana. We found the males much 

 more numerous than the females. The coloration 

 is very striking. They are about as large as the 

 papilios, and the wings of the male, for three-fourths 

 of their length, are of a rich velvet-brown. The 

 1, order, perhaps half an inch wide, is of a brownish- 

 1 range, with the veins marked with brown, and a 

 raw of spots of the same color in the orange. The 

 under side is similar, though the colors are less 

 I rilliant, and some of the characteristic silver 

 markings of the genus appear. When the butterfly 

 is at rest, the resemblance of the folded wings to a 

 ilried and withered leaf is very perfect. 



The appearance of the female is entirely diflierent. 

 The whole upper side is greenish or bluish-black. 

 .\long the outer third of the fore wing run three 

 rjws of pale-blue or whitish spots. On the hind 

 v.ings, the markings are more like those of the 

 male, except that the colors are blue-black and 

 light-blue. On the under side, the base of the fore 

 \v ings is similar to that of the male, except the color, 

 Ij It the tip has a large brown patch, with a dash of 

 M hite, edged with silver, while there are white 

 r:iarkings along the edge. The hind wings are dark- 

 ! rown, with a few markings, and with a grayish 

 1 itch at about the middle of the edge. Like the 

 i.ale, it is well protected when at rest by the re- 

 i mblance to a dead leaf. 



In coloring, this species is an exception to the 

 1^; meral rule. In most genera, where there is a dif- 

 I rence between male and female, it is the latter 

 \ liich has most of the characteristic markings of 

 1.12 genus. In Arijynnis diana, however, it is the 

 i.ale which most resembles the rest. So great is 

 lii'j difference in appearance that, though we found 

 two females with perhaps adozen males, and a num- 

 l r of papilios, feeding on some composite, we had 

 n > suspicion of their identity till we looked them up 

 ill the text-books after our return. 



Now, according to Darwin, when the male and 

 female differ, the one which differs least from the 

 other memljers of the genus is the one which has 

 suffered least modification. Therefore, it must be 

 the female of this species which has been most 

 changed. The next question is, "Why.?" It can 

 hardly be for beauty, at least if our human taste is 

 judge, for the males are fully as beautiful as the fe- 

 males. Can it be for protection ? We know that 

 many species are protected by their color and shape, 

 and we have seen that this very butterfly has the 

 under side of its wings colored, so as to protect it; 

 but is the female less conspicuous than the male.' 

 No one who has seen them will claim that. The 

 only way in which I can see that it may be protected, 

 is by its possible resemblance to some butterfly, the 

 taste of which is oftensive to its worst enemies — the 

 birds. The only species, known to the writer, which 

 it resembles, is the Limenitis vrsula, whose general 

 color is the same, but which is rather smaller. We 

 did not see the latter, but that is not remarkable, 

 since our tramp was .so brief. Neither are we able 

 to state whether it is unpleasant to the taste of 

 birds, though it must be admitted that the probabil- 

 ity is against it, for its nearest relative, L. disippiis, 

 is eagerly sought by birds, but is protected by its 

 almost perfect resemblance to another common 

 species, Danais archippiis, commonly known as the 

 milkweed butterfly. 



This matter of the color is extremely interesting, 

 but, in this case, it is pretty hard to explain why the 

 female difters so much from her mate and their 

 relatives. 



[Specially Reported for The Popular Science News,] 

 METEOROLOGY FOR APRIL, 1S89. 



TEMPERATURE. 



and 8.50 in 1870. The heaviest amount (1.52 inch) 

 fell on the ist. On the 26th, .90 inch fell, and .66 

 on the i8th, and the remaining .4 on five different 

 days. Only .12 inch fell between the 3d and 17th, 

 when the need of rain was becoming apparent, — a 

 want moderately supplied during the remainder of 

 the month. 



PRKSSURE. 



The average pressure the last month was 29.960 

 inches, with extremes of 29.43- on the 28th, and 

 30.35 on the i6th ; a range of .92 inch. The average 

 for the last sixteen Aprils was 29.896, with extremes 

 of 29.767 in 18S4, and 30.07S in 1886; a range of 

 .311 inch. The sum of the daily variations was 

 5.14 inches, giving an average daily movement of 

 .171 inch, while this average in the last sixteen 

 Aprils has been .176, with extremes of .139 and .239. 

 The largest movements were .34 on the 26th, .32 on 

 the 22d, and .30 on the 9th and 14th. There were 

 four principal atmospheric waves or tides during 

 the month, and these were quite gentle and more 

 uniform than usual, occurring at nearly equal inter- 

 vals, the depressions being on the 3d, 12th, 21st 

 and 28th. 



WINDS. 



The direction of the wind, in 90 observations, gave 

 13 N., I S., 8 E., 14 W., 19 N. E., 12 N. W., 6 S. E., 

 and 17 S. W., — an excess of 20 northerly and 10 

 westerly, over the southerly and easterly, and indicat- 

 ing the average direction to have been W. 63^^^ 26' N. 

 The westerly winds have imiforml_)' prevailed over 

 the easterly in April, with but two exceptions in 

 twenty years, by an average of 24.65 observations, 

 and the northerly over the southerly, with but a 

 single exception, by an average of 21.30, — indicat- 

 ing the approximate general average direction of 

 the wind in April to be W. 40"^ 50' N. The relative 

 progressive distance traveled by the wind the past 

 month was 11. 18 units, and during the past twenty 

 Aprils, 651.6 such units, an average of 32.58, show- 

 ing nearly three-told more opposing winds the past 

 month than usual. D. W. 



Natick, May 3, 1889. 



The lowest point reached by the mercury the past 

 month was 31°, on the 8th; the highest, 77", on the 

 20th. The coolest day averaged 35*^, on the ist, the 

 mercury standing at the same figure, 35°, at the 

 three hours of observation — a cloudy, rainy day. 

 The 20th was the warmest day, averaging 66.66". 

 The whole month was nearly 4" above the average 

 of April for nineteen years, and has been exceeded 

 but twice during this period, viz. : in 1878 and 1886. 

 The three warmest days came together — 19th to 21st 

 — with an average of 63.78". The most sudden 

 change was a fall of 20" in twenty-four hoins, from 

 the 2 1 St (noon) to the 22d. A warm spring, thus 

 far, following a remarkably warm winter, has caused 

 the season to be from two to three weeks earlier 

 than last year, and nearly two weeks earlier than 

 the average. 



SKY. 



The face of the sky, in 90 observations, gave 41 

 fair, 17 cloudy, 24 overcast, and 8 rainy; none 

 snowy; a percentage of 45.6 fair. This average the 

 last nineteen Aprils has been 51. i fair, with ex- 

 tremes of 32.2 in 1S78, and 70 in 1872. It has been 

 less fair than the present April only four times dur- 

 ing this period. Thunder and lightning occurred 

 on the afternoon and evening of the 20th and 21st. 

 The mornings of the 19th and 26th were foggy. 



PRECIPITATION. 



The amount of rainfall the past month was 3.67 

 inches, while the average for the last twenty-one 

 Aprils has been 3.97, with extremes of 1.20 in 1869, 



[Specially Computed Tor The Popular Science News.] 



ASTRONOMICAL PHENOMENA FOR JUNE, 



1889. 



The sun will be eclipsed on the morning of June 

 28. The eclipse will be annular, and will be visible 

 only in the southern hemisphere. The central line 

 begins in the South Atlantic Ocean, passes through 

 South Africa, and ends in the Indian Ocean, west of 

 Australia. 



At the beginning of the month. Mercury is an 

 evening star, and sets about an hour and half after 

 the sun. It can be seen in strong twilight, soon 

 after sunset. It passes inferior conjunction and be- 

 comes a morning star on the morning of June 19, 

 but does not get far enough away from the sun to 

 be easily seen before the end of the month. Venus 

 is a morning star, rising about two hours before the 

 sun on June i, and nearly three hours before on 

 June 30. It attains its greatest brilliancy on June 5, 

 and can probably be seen in full sunlight, if one 

 knows where to look for it. Mars is too near the 

 sun to be seen. It passes conjunction on June 17, 

 and becomes a morning star. Jupiter is in the con- 

 stellation Sagittarius, and is slowly retrograding, 

 moving westward about 4" during the month. It is 

 in opposition with the sun on June 24, and is then 

 on the meridian about midnight. The following 

 eclipses of his satellites are visible in one part or 

 another of the United States. The planet has now 

 reached the part of its orb't where the fourth satel- 

 lite is eclipsed, which has not been the case for 

 some time. Before opposition the phenomena take 

 place near the upper left-hand quadrant, and after 



