72 SOME REMARKS ON HARVEY’S DUIKER 
It appears to be well known to the Nandi people (Hollis, 
‘ The Nandi,’ pp. 124-5), and is named ‘ Minde.’ 
The most likely way to shoot this animal is to station one- 
self with a shot gun in the forest where two tracks meet, and 
then to get a few natives to make a detour and quietly to walk 
through the forest towards you. 
This I found to be much the most certain method of getting 
one, as one may visit the forest glades evening after evening 
and never see one, so nocturnal are they in their feeding. 
The flesh of the South African species ( C . naialensis) is 
said to be unpalatable to Europeans, but I have found our 
East African variety to be excellent eating. 
Note . — The simplest distinction between Harvey’s and 
Isaac’s Duiker is the difference in the colour of the head tuft. 
In Isaac’s Duiker the hair of the forehead is mixed rufous 
and black with the surmounting tuft tending to chestnut, 
in Harvey’s Duiker the forehead is black and there is no 
chestnut in the head tuft. 
In addition to the localities mentioned in the paper Harvey’s 
Duiker has been found at the Coast. The maximum recorded 
length of horns of this species is 3| inches. — Editor. 
MIGRATION OF BUTTERFLIES 
By C. W. Hobley 
More information is required with regard to the flights 
of the enormous number of butterflies of the Pieridae group 
which periodically occur in the uplands of British East Africa. 
It is of interest to inquire what species compose the crowds 
of migrants. Some say that Synchloe johnstoni is the commonest 
migrant, but the only large mob that I recollect having seen 
I believe mainly consisted of Belenois severina. The direction 
and distance of the flight are interesting to observe. Those 
I saw were flying from N. to S., and some say this is the usual 
direction. If so, why should it be ? It is also important to 
notice if the migrants were of both sexes or only males ; the 
