38 EINAR LÖNNBERG, STUDIES ON RUMINANTS. 



plane of the eyes, then curving upwards, forwards and inwards, but their tips widely 

 separated, and not coming within the lines of the lateral borders of the skull; their basal 

 anterior surfaces in old bulls raised into huge convex bosses, nearly meeting in the middle 



of the forehead» . The proxiinal part of the horn from the basal bosses to the 



curvature is strongly flattened fi-om the sides, the expansion decreasing in a distal direction. 

 In the curve the degree of flattening is expressed by the proportion 4 : 5 between the 

 diameters. Further distally the horn becomes nearly cylindrical, and the tip is even com- 

 pressed in the opposite, antero-posterior direction. The horny sheath has a considerable 

 thickness especially at the basal boss, where it varies from 2V2 to 4V2 cm. in section. 

 In the portion of the horn between the base and the curve the sheath is thicker (about 

 10 mm.) on the side, corresponding to the concave one of the curve, less thick (7 — 8 mm.) 

 on the opposite side. Just in the curve the dimensions are different, the diameter of the 

 concave side being 12 — 13 mm. and that of the convex 15 — 16 mm. Further distally 

 the thickness of both sides is subequal. The resp. upper, lateral, or concave side is the 

 stretched side, when the horn is used. It is accordingly useful that the elastic horny 

 material is thick on that side. The great development of the horn of the basal bosses 

 is useful in making tlie fixation of the sheath to the skull quite tirm and reliable, in a 

 manner described below, and is also of great importance when the animals butt with their 

 foreheads. The bony core extends through somewhat more than 80 % of the entire length 

 of the horn. In correspondence with the general shape of the horn the core is strongly 

 flattened especially in its proximal part. Posteriorly it is, below the boss, expanded into 

 a rather broad and thin edge, anteriorly there is a distinct angle although not so much 

 compressed on that side. The surface of the basal parts is very rugged and rough with 

 protruding warts and small knobs, which correspond to and and fit into grooves and pits on 

 the inner surface of the horny sheath. By this arrangement which occupies the very great, 

 expanded basal area the horny sheath is very firmly attached to the skull. At the first 

 look this seems to offer a great resemblance to the condition found in Ovibos. There is, 

 however, this difference. In the base of the horn of the musk-ox there are Avarts and 

 small knobs on the inner surface of the horn, which are sunk into corresponding pits of 

 the bone of the basal core, and in the Caffer buffalo the prominences belong to the bone 

 and the pits are found in the horny material. Another considerable difference between 

 the horns of these two animals is the shortness of the bony cores of the musk-ox and 

 still another is the nature of the basal parts of the bony tissue covered by the »bosses» 

 of the horns. In Ovibos they are solid exostoses on the frontals, in the Caffer buffalo as 

 in the gnu they are the protruding sinuous bases 01 the core. The two latter animals 

 also resemble each other with regard to the mode of attachment of the sheath to the core, 

 for in both the warts and prominences sit on the core and are sunk into pits in the 

 horny mäss. The base of the core of the Cape buffalo has been said to be occupied by 

 a great sinus. This sinus is divided in a number of cells of varjdng size by means of 

 solid lameilar trabeculse of compact bony tissue. These are arranged vertically against 

 the frontal surface and mostly extended in the direction parallel to the main axis of the 

 horn. The cells get then a similar extension. Thanks to these numerous walls of the 

 cells (and the thick horny sheath) the roof, so to say, that is the frontal wall of the 



