MISCELLANEOUS NOTES. 533 



No. V.— THE MIGRATION OF BUTTERFLIES. 

 , By migration in the case of butterflies one means the frequently observed 

 habit of the insects of flying in a certain direction, or, to speak more ac- 

 curately, on one route. They follow one another in hundreds, a steady 

 continuous flow, seldom more than half a dozen or so passing at the same 

 time, but the stream never stops for hours. Usually the flight is against the 

 wind, which suggests that the butterflies are following the scent of some flower 

 or that they are really meeting the pollen of their food plant up the wind ; 

 the real difficulty is to account for these processions in any manner which 

 shall show some symptom of reasonableness. The Danaince are the most often 

 observed in the act of migration, and 1 well remember the first procession 

 that was shown me by Mr. Davidson at his camp at Siddapur, in North 

 Canara. This consisted entirely of the common Danaince and was passing 

 steadily across the front of his tent for at least two hours under my observa- 

 tion. A week ago, in the course of my duty on Mody Bunder, I watched a 

 procession of Euplwa core passing down the harbour just clear of the bunder ; 

 they were passing for certainly an hour, and may have gone on long after I 

 had left the place. Many hundreds of butterflies must have passed me in 

 this hour. There are several points of interest in the occurrence ; the first 

 one suggesting itself to any one who has reared butterflies is the entire im- 

 possibility of breeding so large a number as you may see passing you in one 

 of these migrations in anything but a large area ; to follow up this line of 

 suppositions it is manifest that if they were not all bred ia one place they 

 must have assembled after hatching ; and finally if they were bred as I 

 suppose over a large area they must have assembled to migrate in response 

 to some call not yet appreciated by the intellect of man. 



S. E. PRALL, Surg.-Captain. 

 Bombay, 28th October, 1897. 



No. VI.- SPEED OF FLIGHT IN BUTTERFLIES. 



During the monsoon in travelling by rail from Bandra over the Mahim 

 creek it has been interesting to note the way in which butterflies of all condi- 

 tions and sizes have used the railway causeway as a road of safety to cross the 

 water of the creek which is at this point of considerable width, probably 

 nearly a mile. On a fine m orning looking from the carriage windows one 

 could very clearly see the way in which the crowds of butterflies flew steadily 

 over the embankment with its flowers and grasses and avoided the water. T\ e 

 difference in the number of butterflies seen on this particular embankment' and 

 others with practically the same vegetation, would seem to warrant the 

 supposition that insects were using the bank as a safe road from the one side 

 to the other. The trains run over this part of their journey at speeds varying 

 from seven to fifteen miles an hour, and while most butterflies seemed to be 



