2 HEER F. E. BLAATJW 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 Antelope bred in the writer's menagerie, was read : — 



" 534 Heerengracbt, Amsterdam, 

 December 1888. 



" Sir, — I am now able to send you the long promised drawings 

 showing the development of the horns of Catoblepas ynu. 



" 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 and forlorn, and give the young animal 

 quite an idiotic expression. For a time the horns grow straight, and 

 stand nearly vertically on the head ; but gradually the points begin to 

 diverge from each other, which divergence is at its greatest develop- 

 ment at the age of eleven weeks (fig. A). At this age what afterwards 



Fig. A. 



S{ 1,// 



Horns of joung Catoblepas gnu. 11 weeks old. 



become the straight points in the adult {a-b, fig. D, p. 4) have 

 come out entirely, and the parts c-b (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 c, 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 c-b, 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 Hke fig. B. This goes on until at 19 months 



