1907-.] 



HORNS OF THE GIRAFFE. 



107 



The substance of the young ossicone was free from osseous 

 deposit but of a tough consistence. Microscopic sections showed 

 it to consist of a fibro-trabecular tissue with abundant interspersed 

 celhilar elements. 



The dissection as here presented definitely establishes the fact 

 that the site of origin of the lateral horns or ossicones of the 

 Giraffe is entirely within the area of the parietal bone. The 

 supposition that Sir Richard Owen had by inadvertence reversed 

 the cut-out portion of the fronto-parietal area of his newly-born 

 Giraffe, and had thus identified parietal as frontal and frontal as 

 parietal, is confirmed. The importance of the distinction between 

 the genus Giraffa and the genus Okcqna, arising from the parietal 

 position of the lateral ossicones in the former and their frontal 

 position in the latter, is thus placed on a firm basis, since it is 

 shown that at a stage of growth even earlier than that of birth 

 the "forecast" or rudiment of the Giraffe's lateral bony cone 

 (ossicone) is placed and attached absolutely and solely within the 

 area of the parietal bone. 



Text-fi2-. 31. 



A. B. 



The left " horn " of the foetal GirafFo, drawn of the natural 



A. Seen from behind (postero-external face). 



B. Seen from in front (antero-internal face). 



The form of the soft unossified forecasts of the lateral ossi- 

 cones in this fcetal Gii'afle is worthy of further notice. As shown 

 in Plate Y. accompanying a later paper in this volume, and in the 

 text-figure here given (fig. 31), the upgrowth is of considerable size, 

 is compressed so as to give a nari-ow oblong area in transverse 

 section, and is set on the head so that the elongated basal area 

 has an oblique position, with its long diameter directed back- 

 wards and inwards towards the median line. The surface of the 

 ossicone-forecast is covered with hair, which is very coarse and 

 long at the free upstanding margin, as shown in text-fig. 31. 



