HARDWICKE*S SCIENCE-GOSSIP. 



221 



MIGT^ATION OF BUTTERFLIES, JAMAICA. 



IT is desirable to place on record the migration of 

 butterflies which we have witnessed in Jamaica 

 this year. I first noticed that butterflies were steering 

 a defined course on the first Sunday in May, but they 

 had been unusually numerous for some days before 

 that. Their course was from south-east to north-west. 

 During the whole of May, and far into June, the 

 migration continued, and always in the same 

 direction. Singularly, very few entered houses. 

 Their numbers varied from day to day, but occa- 

 sionally one might have said, as Darwin's sailors 

 of the Beagle did, that it was snowing butter- 

 flies. The air was thick with them. In the evenings 

 the drift slackened, and some of the trees near my 

 house would be covered with as many butterflies as 

 leaves. 



I have no information as to their starting-point, but 

 during the time they were passing Kingstown, I was 

 informed that the flight had been met with by sea- 

 men near the Cayman Islands in long. W. 80°, 

 about 100 miles north-west of Jamaica. 



A friend gives me the names of the butterflies as 

 Synchloc joppa (Boridv.), Kricogortia terina (Luc), 

 Callidryas semtcc (Linn.), and Amynthia mccriila 

 (Fabr.). The first three were in myriads, the last 

 common, and I am doubtful how far its movements 

 were migratory. I am told that these swarms of 

 butterflies are well known here ; this is the first 

 time I have remarked them in a residence of four 

 years. 



The migrations are certainly not of the annual 

 character they are in Ceylon, where I have seen them 

 year after year j there they were never so prolonged, 

 or the butterflies so numerous. Emerson Tennent 

 gives as the butterflies taking part in the Ceylon 

 migrations Callidryas hilariu:, C. alcmeojie, C. py- 

 ranthe, with straggling individuals of the genus 

 Euplcea. 



All flights of butterflies have not -the same direc- 

 tion. In Alabama in 1S90, (United States Govern- 

 ment Entomological Journal, April 189 1), Callidryas 

 enhile migrated from north-west to south-east. One 

 recent flight was from south-east to north-west. 

 Lyell speaks of Vanessa cardui flying from north to 

 south. Tennent's Ceylon butterflies fly north- 

 easterly. Kirby and Spence mention a migration of 

 bugs going west. 



In these migrations an understood purpose there 

 can hardly be ; failure of food may compel emigra- 

 tion, but would not give direction. What impulse 

 within or, it may be, compulsion without gives 

 unanimity of effort to these myriads, and the 

 resemblance of set purpose? What directs their 

 flight, and what is the end of their journeyings ? 



J. W. Plaxton. 

 Kingston, Jamaica. 



CHEAP BREAD. 



AS a rule the price of grain, and that of wheat in 

 particular, rises in this country when there are 

 most, and again when there are fewest spots upon the 

 sun, and then we may expect an outcry among 

 agriculturists and commercial panics. We have, 

 thanks to Professor Thorold Rogers (" A History of 

 Agriculture and Prices in England "), over six 

 centuries of corn statistics, and thanks to Professor 

 Wolf, over three centuries of sun-spot statistics, to 

 substantiate these assertions. Firstly, then we 

 gather, that the following have been the years of 

 most and fewest sun-spots, as observed by astronomers 

 since the employment of the telescope in Europe. 

 1610, 1615, 1619, 1626, 1634, 1639, 1645, 1649, 

 165s, 1660, 1666, 1675, 1679, 1685, 1689, 1693, 

 1698, 1705, 1712, 1718, 1723, 1727, 1734, 1738, 

 1745. 1750. 1755. 1761, 1766, 1769, 1775, 1778, 

 1784, 1788, 179S, 1804, 1810, .1816, 1823, 1829, 

 1833. 1S37, 1843, 1848, 1855, i860, 1867, 1870, 

 1878, 1882. Since the average spacing of these years 

 is alternately eight and three years, it evidently 

 follows that commencing with the mean year 1612, 

 and substracting eight and three alternately, we may 

 in approximation continue this series backwards : or 

 commencing with the mean year 1887 and adding 

 three and eight alternately, we may continue it 

 prophetically forwards, leaving the revelation of the 

 exact epochs to astronomers. Secondly we gather 

 that the following years are those in which grain, and 

 more especially wheat, has been highest in price in 

 the United Kingdom. 1259, 1262, 1271, 1274, 

 1283, 1290, 1294, 1299, 1304, 1309, 1316, 1321, 



1331. 1339, 1346, 1351. 1357. "^i^^z^ 1369, 1374. 



1380, 1384, 1390, 1396, 1400, 1409, 1416, 1420, 

 1426, 1432, 143S, 1445, 1450. 1457. 1461, 1469. 

 1477, 14S2, 1491, 1496, 1501, 1507, 1512, 1520, 



1527, 1536, I545> 1551, 1556, 1563. 1566, 1573. 

 1577— 1648, 1659, 1661, 1665, 1674, 1679, 1685, 

 1688, 1693, 1698, 1704, 1709, 1720, 1725, 1728, 

 1735. 1740, 1746, 1753, 1757, 1764, 1767, 1774. 

 1777. 1783. 1790. 1796, 1801, 1812, 1816, 1825, 

 1S31, 1S39, 1844, 1847, 1855, 1862, 1867, 1873, 

 1877, 1881. As the former portion of this series of 

 years, for the possibility of whose determination w 

 are indebted to Professor Thorold Rogers, have the 

 same intervals as the latter portion extracted from 

 Government statistics ; it becomes apparent that they 

 in like manner approximate the epochs of most and 

 fewest sun-spots ; an impression that will be further 

 confirmed on extending that series backwards in the 

 manner suggested ; so that it only remains to show 

 why any particular years in the series do not exactly 

 coincide with these epochs of most or fewest sun- 

 spots. " Rain, rain, go to Spain," says the nursery 

 rhyme ; and here it strikes me this might occur from 

 the circumstance that the year of most sun-spots is 



