LONKBERG, MAMMALS. 37 



raff es are butting such lesions take place in many of the more or less exposed parts of 

 the skull and this accounts for the generally rugged surface of the facial bones as may 

 be seen as well on the accompanying figures of the Kilimandjaro Giraffe as on LYDEK- 

 KER'S quoted figure of the South Lado Giraffe. But this ruggedness is, at least in the 

 present specimen, much more pronounced on the right side of the skull, as it ought to 

 be according to the hypothese of the right-headedness of this animal, because this 

 side is more apt to be hurt. In the most exposed places which are repeatedly hurt tin- 

 results of the reiterated irritation are accumulated and thus finally greater exostoses, 

 bosses - - horns are created. But then the originally semipathological structures 

 become useful, partly because they shield underlying organs, partly as weapons. 

 The results of the right-headedness is, however, not only shown by the osseous excre- 

 scences on the surface of the skull. As the right side of the head is so to say the busi- 

 ness-side i> it has needed a strengthening in a general way to endure the work and such 

 a strengthening has evidently to some degree taken place as may be proved by compa- 

 ring measurements from both sides. The increased size, especially thickness, of the right 

 parietal horn has already been noted above. To this may be added the following: 



Right Left 



Thickness of posterior wall of orbit at the middle . . . , 2f> ram. 21 mm. 



Breadth 44 ' ,. 39 



(i. e. prurfx>i/tx friiHtdlis of jugale) 



Thickness of jinj/ili just behind the orbit .......... 18 IB 



Breadth . 32 2* 



Length of processus parwnastoideus from ynQyin ini'ii/na timl'itui-iux 63 HI 



In a similar way almost all measurements of the hindpart of the skull are a little 

 larger on the right than on the left side. On the occipital surface this is especially con- 

 spicuous. Stj IHI HIM occipitalis shows a central fossa or groove ior ligament K in n itchie divided 

 from the likewise somewhat concave lateral portions by a heavy and solid thickening on 

 either side which from the upper lateral corner of the occiput converge into a big boss 

 just above foramen magnum. These thickenings form like two pillars supporting the 

 weight of the cranial roof behind. But the right of these coming from the occipital 

 exostose mentioned above is much larger than the left not only in breadth (37 mm. in 

 the former, 33 Va in the latter) but especially in thickness. 



On the other hand the left condyle is larger than the right, the former mea- 

 suring 66 mm., the latter 64 mm. in length from upper, outer corner of posterior 

 surface to lower, inner angle of the same, and resp. 46 and 44 mm. in breadth along 

 the upper margin of the posterior surface. This may probably be in accordance 

 with mechanical laws as well. The right condyle forms the pivot on which the 

 skull turns when the animal butts with its right side and then it is suitable that 

 this is not unnecessarily wide. But the left condyle, or rather the connecting tissues 

 round the same, have to endure a certain straining when the head is violently thrown 

 towards the right side. The power of resistance is in such a case increased by the 

 enlargement of the condyle. 



