2 HEER F. E. BLAAUW ON CATOBLEPAS GNU. _[Jan. 15, 
The following letter addressed to the Secretary by Heer F. E. 
Blaauw, of Amsterdam, relating to the development of the horns of 
the White-tailed Gnu (Catoblepas gnu), as observed in several ex- 
amples of this Autelope bred in the writer’s menagerie, was read :— 
“534 Heerengracht, Amsterdam, 
December 1888. 
“Srr,—I am now able to send you the long promised drawings 
showing the development of the horns of Catoblepas gnu. 
‘The drawings were taken from a female born July 22nd, 1886. 
When the young Gnu is born the forehead is covered with thick 
shining hair of a rich chestnut colour, and the places for the horns 
are marked by little tufts of hair. 
«When the young animal is five or six days old the horns begin 
to show through the tufts. Remarkable is the position of the ears, 
which, being made for afterlife, when they are partially covered by the 
heavy horns, look very long forlorn, and give the young animal 
quite an idiotic expression. - For a time the horns grow straight, and 
stand nearly vertically on hs head but gradually the points begin to 
diverge from each other, whieh divergence is at its greatest develop- 
ment at the age of eleven weeks (fig. A). At this age what afterwards 
Fig. A. 
Horns of young Catoblepas gnu. 11 weeks old. 
become the straight points in the adult (a—d, fig. D, p. 4) have 
come out entirely, and the parts c—d (fig. D) now begin to make their 
appearance, during which process the points assume altogether a 
different position. It is worthy of notice that even at this early 
period, when the top of the head is as yet quite covered with hair, 
the place and form of the horny parts (d and e¢, fig. D) in the adult 
are already visible. This also shows that the points of the horns 
begin to grow out of the head considerably lower in position than 
where the future bases of the horns will be. 
“ The part e—d, fig. D, is now developing, the horn is driven for- 
wards, downwards, and sidewards at the same time, and at the age 
of 16 months looks like fig. B. This goes on until at 19 months 
