KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 35. N:0 3. 19 



tissuc, which, howe\er, is traversed by a great number of canals for nourishing blood- 

 vessels. The canals are larger than the fine pores in the core of Saiga, but the tissue 

 is more dense than the »tubular» one of Gazella dorcas. The condition of this part of 

 the core of Antidorcas is thus intermediate, and it may be regarded as compact tissue 

 perforated by many canals. The distal two thirds, approximately, of the springbuck's core 

 have a different structure. There can namely, in these parts be discerned an outer com- 

 pact and an inner spongious layer. But the spongiosa is also different in different parts. 

 Just within the peripherical conipacta, especially on the posterior side, the elements of 

 the spongiosa are longitudinally extended so as to form a rather dense tubular structure, 

 but further inwards and towards the anterior side the meshes become luore irregular and 

 the interspaces larger. At the middle of the core in this loose centi^al ^) spongiosa some 

 obliquely transversal trabeculse may be distinguished. These are arranged in such a way, 

 that their inner end is situated further distally and the peripheric end more proximally 

 in the core. These trabeculse can, to judge from their arrangement, be considered as 

 trajectories in accordance 'with Cdlmann's law. They belong however to an incomplete 

 system, as they are only developed on one, the anterior, side. They are also less regular 

 than in the coi'e of some other animals (as for instance Rupicapra). Towards the tip 

 of the core, where it is protected by a thicker horny sheath, the bony tissue is more 

 spongious than elsewhere and the trabeculaj cannot be discerned. At least peripherically 

 the elements are, however, more or less longitudinally extended. Distally the outer com- 

 [lacta is thicker on the posterior side. When the horn of Antidorcas has been longi- 

 tudinally sectioned in the sagittal plane and divided into two halves, there may be seen 

 on the interiör surface of the lateral half of the hoi-ny sheath a rather strong longitudinal 

 i'idge, which corresponds to a groove on the surface of the core. This ridge braces the 

 core against violence from the side and helps to fästen the sheath on the core. The rings on 

 the horns add essentially to the beanty, but from a mechanical point of view they may also 

 be regarded as being not only of protective use against torsion and corrugation of the sheath 

 on the pressed side, but also against breakage, as they are not quite transversally arranged. 

 In such cases, when the tips of the horns of Antidorcas are turned towards the median 

 side, it is not easy to understand how they are used. With regard to this Darwin quotes 

 Bartlett, who suggests that »they would inflict a fearful wound down on each side of 

 the face of an antagonist». When the tips, as in the specimen investigated by the present 

 writer, are directed backwards, they can of course be used for hooking and dealing blows 

 from below upwards. The posterior side is then the strained side of the lever. It is conse- 

 quently proper that the elastic horny sheath is more strongly developed on that side, as 

 we have seen it is. The thick and short compact wall on the posterior side of the basal 

 sinus and its strong fisation to the skull is also a suitable adaption to withstand the 

 pulling force. The same might be said about the longitudinal extension of the elements 

 of the spongiosa. The pressed side is also rather strong. The horny sheath is not much 

 weaker on that side and, as has already been stated, its rings prevent corrugation. The 



^) It is uot quite central but a little nearer the anterior side, due to the stronger developraent of the 

 tubular structure on the posterior side, as has beeu stated. 



