Butterfly Migrations in British Guiana. 335 



of the side channels of the fall, Mr. Winter is unable to 

 give the direction of the flight. This was the first such 

 migration Mr. Winter witnessed. 



4. Essequibo River, Mocco-mocco Point, February 1914, 

 Mr. Winter says : " I was camped there for two or three 

 days and on one day there was a stream of these yellows 

 coming across the river from east to west in twos and threes 

 with gaps between. The fhghfc lasted all day — say between 

 7.30 a.m. and 4 p.m." From the position of his camp 

 Mr. Winter is unable to give an idea of the width of the 

 swarm. 



5. Mr. G. F. Messervy, of the Department of Lands and 

 Mines, who has been stationed at Christianburg on the 

 Demerara River for the past three years, gives me the 

 following observation. 



He observed a migration of yellow butterflies in May 

 or June 1916, on the Demerara River about 140 miles 

 from its mouth. The insects were flpng from west to east 

 in batches of about twenty or so. They were yellow mixed 

 with some paler-coloured ones. This was about the 

 beginning of the wet season. Mr. Messervy cannot say 

 definitely whether it was in May or June that he observed 

 these insects. 



Resting in Patches. 



The four following observations by Mr. Winter on the 

 resting of these insects in patches are interesting. As to 

 whether they were obtaining some nourishment from the 

 sand in the form of salts is problematical, but the suggestion 

 made by Wilhams with regard to the urine from animals 

 would certainly not hold good in at least the last three 

 instances, whilst even in the first it is hardly hkely, for not 

 more than a couple of animals — mules — pass along this 

 road each day. 



6. Potaro Road, 7f miles from Potaro Landing. Septem- 

 ber 1915. Dry season. A number of yellow and greenish- 

 white butterflies, some with a distinct orange tinge, were 

 resting in the middle of the road in bright sunlight on a 

 sandy patch over an area of about | to 1 square yard. 

 The butterflies seemed to be collecting at this spot from both 

 sides of the valley out of the forest. (The Potaro Road 

 is in the Mahdia Valley between Eagle Mt. and the Kaiteur 

 Mountains.) The insects were packed close together, 



