26 felNAR LÖNNBERG, StUniES ON RUklNANT^S. 



sheath is also prevented by the ribs. From all this inay be seen that the horns of 

 Buhalis caama are wonderfully well adapted as weapons from a, raech;inical point of view. — 

 Other species of this g-enus migiit in the same degree as the shnpe of theii- horns resemble 

 the same of this aiiimal also show a similar structure. — Vrolik has figured of longitudinal 

 section throngh the horn of Bubalis caama in »Verhandelingen der Kon. Akademie van 

 Wetenschappen, Amsterdam 1854/) but in this the mechanicnl structnres of this organ 

 are not represented, beciuise lie seerned in this paper to have laid most stress oii proving 

 the presence or nbsence of the l^asal sinus of the horns. 



Of the genus Dainali.^cus I have not had material for investigation of the strnctnre. 

 An inspection of the exteriör of the horns of foi" instance Sundewai-ls' »Buhal/y kohay> 

 {=-- Damaliscv.^ iiang (Heuglin)) indicates that they are a.dapted foi- use chiefly in the 

 sagittal plane. They are therefore compressed from the sides, ;md corrugation of the 

 sheath is prevented Ijy the development of trans^•er8al ril)s in front. The tirm attachnient 

 of the horns to the skull is effected ])y their basal enlargeraent. Allied species have 

 similar horns. Those of DaiiKilisrus [n/gari/ifs" ;ind D. nlhifrons seeni to be still more 

 compressed at their Isases. 



The hookshaped horns of the whitetoiled gnu corres])onds naturally to the distal 

 curve of the horns of Buhalis cnania ;ind consequentlv resembles the s;ime, to ;i certain 

 degree, Avith regiird to its structure. It is, howcAer, more specialised in soine respects, 

 although its core, in which perha])S the mnin strength in this case is founded, is more 

 solid aiid compact (Conf. tig. 13 Pl. 11). The core extends throngh (approximately) 88 %/ 

 of the entire length (60 cm. along the oiiter curve) of the horn. Its bnsal parts forming 

 (■le\'ations of the forehead ai'e occupied l)y a large sinus corresponding with the fi-ont;d 

 ones. In and from the roof of these ])asal sinuses hne longitudinal elements of the bony 

 tissue are seen to extend in ;i distal direction in the upper half of the core. At some 

 distance, 5- — 6 cm., from the sinus they disappear, being fused with the upper compacta. 

 The lower half of the s]iongiosa in this most ])r()xim;d region does not show any regular 

 trabeculfe. A few, 4 oi- 5, centimeters from the basal sinus some indistinct trajectories 

 inay be traced, extending from the lower side of the core towards the centre. A cou])le 

 of centimeters fui'ther distally trajectories of the opposite system may be more plainly 

 seen running across the central spongiosa. Trajectories of this system may l)e followed 

 to the curve and still further although they become less conspicuous distally, owing to 

 tiie fact that the core becomes nlmost entirely compact all through. The compact bon\- 

 tissue is, na.mely, very mnch developed in the core of this animal. In the proxinuil third 

 of the core the upper (that is on the inner side of the book) com])acta measures alsout V:i 

 and the lower (that is on the» outer side of the hook) one '/s of the thickness of the core. 

 The layers become, however, still more thickened distally, so that they meet in the centre 

 of the core. In consequence hereof it may be said that 14 cm. from the sinus aiid 

 Ijeyond that phice all the way to the tip the core consists almost exclusivelj^ of compact 

 l)ony tissue, although there are some porosities here and there, es])ecially in the middle 

 of the distal third. These porosities aiv distributed in such a way, that trajectoiies can 



1) 1. c. T;il.. 1 



-) (_"oiit'. Ih'1(iw. i ■ ■ ; . 



