KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 35. N:0 3. 39 



sinuous portion of the core, ueeds not be very thick (soine few millimeters) and is in fact 

 even perforated in some places. Laterally the sinus is not so much divided into cells 

 by trabeculfe, and then the outer walls become firm and thick, 1 V2 — 2 V2 cm. or more. 

 It is almost only the base of the core, that portion which corresponds to the boss of the 

 horn, which includes the sinus (Conf. tig. 16 Pl. II). The core itself in a restricted sense 

 is almost entirely solid, the only exception being a narrow prolongation of the sinus 

 which measuring about 1 cm. in diameter extends 4 — 5 cm. in a distal direction. The 

 core is however not only solid but consists also of compact bony tissue, which is only 

 perforated by the canals for the bloodvessels. There is only a small portion of a coarse 

 somcAvhat spongious tissue extending 6 — 7 cm. from the distal end of the sinus and 

 measuring 12 — 15 mm. in thickness. But even in this portion the tissue is firm and 

 the network thick, compared with the interspaces. With regard to the solidness and com- 

 pactness of the core this buffalo agrees with the gnu. The' horns of the Cape buffalo 

 are evidently powerful weapons. Lydekker gives, in his repeatedly quoted work, a description 

 of how a buffalo of this species charges, holding the muzzle nearly straight out and the 

 forehead almost horizontal; »and even Avhen within striking distance the head is not lowered, 

 but turned to one side, and the foe knocked down or gored by a sideway sweep of the 

 massive horns». It is ewident that by these corabined motions of the whole aniraal and 

 its head the main shock strikes the horn in a direction vertical against the longitudinal 

 axis of the horn and in the same plane, in which it has become strengthened by the 

 compression. If the point of the horn has by the »sideway sweep» pierced the body of 

 the foe, the pressure on the tip of the horn, produced by this, tends to effect a torsion. 

 Such a violence, too, is, however, favourably counteracted by the compression, and the 

 sheath cannot be pulled ofi' the core, being strongly fastened in the manner described 

 above. The construction of the horn of the Caffer buffalo is thus from a mechanical 

 point of view well adapted to the mode in which it is used. ■' ■■ ^ * ' 



Although Antilocajyra is an aberrant type, I have for comparison's sake prepared 

 a longitudinal section of the core of such an animal, too. The core of the prongbuck 

 consists nearly exclusively of spongiosa. There seems only to be a basal sheath of compacta 

 which is 3 mm. thick on the inner side, but only IV2 mm. anteriorly. Posteriorly it 

 extends further than on other sides and is partly substituted by a dense spongiosa with 

 longitudinal elements. A streak of a similar spongiosa can also be seen on a sagittal 

 section bordering interiorly the anterior prominence, which carries the secondary point 

 of the horny sheath. The spongiosa of the tip is also rather dense, otherwise the whole 

 of the interiör is occupied by an, as it seems, irregular and rather loose spongiosa. 

 Especially at the base the meshes are large and the structure weak. The main strength 

 of the horn core of the prongbuck lies in its compressed shape ^\'ith the sagittal diameter 

 more than twice as long as the frontal one. The attacks are of course made in the sagittal 

 plane, and thus the horn has sufficient resisting power, thanks to its shape and in spite 

 of its rather weak structure. That the horn is used in the sagittal plane may also be proved 

 by the considerable forward prolongation of the surface of occipital articulation of the skull. 



As a general conclusion drawn from the statements made above it may be main- 

 tained, that the horns of the Cavicornia as a rule are more or less strongly adapted to 



