OCR Text |
Show 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 examples of this Antelope bred in the writer's menagerie, was read :- " 534 Heerengracht, Amsterdam, December 1888. " S I R , - I aim 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 boras 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. Bemarkable 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 development at the age of eleven weeks (fig. A). At this age what afterwards Horns of-young 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 forwards, 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 |