102 MR. C. X. BARKER ON* 



Mr. Spruce's sojourn in S. America he witnessed large flocks 

 of butterflies pass across the Amazons, near the mouth of the 

 Sun ore in Novembf^* 1849, in a direction from N.N.W. to 

 S.S.E., evidently in the last sta<i;e of fatigue, " all of common 

 ivhite and orange yellow species. '' The little wind there 

 was blew from E. to N.E., and therefore tliC butterflies 

 steered their course at rioht anoles to it. 



In (yeylon Sir Emerson Tennent watched the '' extra- 

 ordinary sight of flights of these delicate creatures, generally 

 of white and pale yellow hue, a[)parently miles in breadth 

 and of such prodigious extension as to occupy hours and 

 even days uninterruptedly in their passage." Darwin 

 describes such another "swarm'' which he witnessed 

 when about 10 miles from San Bias. " Vast numbers of 

 butterHies, in bands or flocks of countless myriads, extended 

 as far as the eye could range. Even with a telescope it was 

 not possible to see a space free from butterflies. The seamen 

 cried out it was snowing butterflies^' ; and these again were 

 Pierinae, as Darwin found the most common butterfly 

 to be a species of C^olias. 



The pseudonymous "Eha,'' wdio has written so pleasantly 

 of Natural History in India, observes that "butterflies of some 

 kinds, — especially those greeni-h-white ones of the family sur- 

 named Callidryas [meaning Catopsilia; Callidryas 

 is restricted to American species] ... I have stood near one 

 of the Parade-grounds at Poona and watched theui. With 

 scarce a pause to rest their wings or sip a flower, from 8 or 9 

 o^clock until tlie afternoon, as far as eye could reach, the host 

 kei)t streamintr past like the lugitive Gauls after one of Caesar's 

 great battles." There are many records of the great assem- 

 blages of migratory hosts of the genera Callidryas and 

 Catopsilia. The following, quoted from the late Mr. 

 Tiiuien's " S. African Butterflies'' (Vol. iii, p. 190), recounts 

 the late " Col. Bowker's observation of an imuiense migrating 

 host of this butterfly in Basutoland." He gives it in Col. 

 Bowker's own words as follows : — " During my trip to 

 No-man's-land in March 18G9, I crossed the Maluti Moun- 

 tains at two different points, going and returning; and 



