2!t, EINAH LÖNNBERG, STUDIES ON RUMINANTS. 



receives its peculiiir shape. The sinus do not, however, reach very far in a distal direction 

 above the median junction of both cores, their axial length above this place equalling 

 a little more than half the inner diameter of the basal tubes respectively. The compact 

 walls of the sinus continue in the outer compacta of the core. Anteriorly this compacta 

 is rather stronglj^ developed along the proximal curve, and, accordingly, a thick compacta 

 is there united with a thin horny sheath. On the posterior side the basal compacta 

 gradually becomes dissolved into a heavy spongiosa with small meshes and strong network. 

 On that side therefore hardly any outer compacta can be discerned from a place a few 

 centimeters above the basal sinus and all along the posterior (convex) side of the proximal 

 curve. In the distal curve again, a thick compacta is developed on the posterior (concave) 

 side, but the compacta of the anterior side disappears completely or becomes dissolved 

 into spongious tissue. Thus, the condition is anaJogous, in both curves a compact zone 

 is developed on the concave side and corresponds to a thin portion of the horny sheath, 

 but the convex side which is converted by a thick homy sheath is devoid of compacta. 

 In the intermediate region between both curves the outer compacta is developed on both 

 sides. The main mäss of the core consists of spongious tissue, but is, nevertheless, to be 

 regarded as possessing considerablé power of resistance, because the mechanical systems 

 are well developed and the network thick. The following principal arraugements of the 

 elements of the spongiosa may easily be distinguished on a longitudinal section through 

 this core. ■ — On the figure of the core of this animal (Pl. I fig. 10) these arrangements 

 have been reproduced, but somewhat schematically, because in reality the trabecula^ are 

 so numerous and running so close to each other, that it could not be jslainly copied on 

 a figure of reduced size. The difterent systems of trajectories are, however, all of them 

 represented on the figure, altliough reduced in nuinber and somewhat enlarged. From the 

 posterior wall of the basal sinus there is a number of trabeculai which on the sagittal section 

 show themselves diverging like a fan upward and obliquely forward. In a distal direction 

 from the basal sinus, or on top of the same, trabeculne are seen running from the anterior 

 side nearly straight or a little arched towards the posterior side and somewhat upwards. 

 They are met at right angles by another system of trabeculaä, -which go nearly parallel 

 with the posterior surface, but bend a little towards the centre. The crossing of both 

 systems takes place nearer the posterior than the anterior surface, and at some distance 

 from the base towards the first curve of the core only tlie more transverse trabecula; 

 are seen, the posterior ones becoming dififused in the outer layer of the posterior side. 

 This layer is a rather densc; spongious tissue, in which the elements are longitudinally 

 stretched, although they cannot be very well discerned. In the portion of the core which is 

 intermediate between the two curves, the spongiosa does not contain any systematical trajec- 

 tories, the network seems irregular and the meshes larger than in other places. But in the 

 distal curve again the same arrangement as in the proximal one is repeated. From the 

 concave side a great number of arcuate trabecula? extend transversally towards the convex 

 side and rtieet near the latter another system of traljeculie, wliich are more weakly developed 

 and run almost parallel to the surface (Conf. the figure). The latter disappear completely 

 in the distal end of the core, but the former can be followed nearly to the tip. From this 

 description may be concluded that the horn of Buhalis aiama is very strongly built. 



