Mateeial for the Study of Ruminants. 



45 



but almost wholly covers the right kidney on the ventral side. There 

 is no trace of a gallbladder. 



The spleen is strongly convex on its anterior (diaphragmatic) 

 surface; the dorsal and median portion is much thicker than the other 

 parts which become quite thin towards the margin. It is triangular 

 in outline. 



The kidneys are quite simple and show when cut only a single 

 longitudinal mamilla. 



A comparison of the organs of foetus h. and foetus i. reveals 

 the following facts. The glandula thyreoidea of the former is even 

 comparatively smaller than that in foetus i. measuring only 6 mm. 

 But, on the other hand, the thymus gland of the younger foetus is 

 comparatively better developed as it reaches quite up to the larynx 

 where it is broadened again. The lungs are similar in both. The 

 reticular structure of the inside of the reticulum is feebly developed 

 in the foetus L The psalterium of foetus h. is remarkable for its com- 

 paratively great size which is not far from equal to the same in the 

 foetus i. It measures namely, not less than 12 mm. in length by 6 

 in width. Eight folds are visible although one of the lateral ones is 

 less developed. The size of the psalterium in this young foetus (its 

 length being not far from half the length of the paunch) adds further 

 strength to the theory expressed above that the psalterium of the 

 adult Cephalophus ogilbyi is a, in consequence of the changed diet, 

 reduced organ. The abomasus has in the younger foetus the same 

 interior structure as in the older. With regard to the arrangement of 

 the colic coils there is an interesting difference between the two foe- 

 tus. In the older one (i.) the coils are more drawn out longitudinally 

 and partly cover each other. In the younger (It), all coils lie nearly 

 in the same plane so that hardly any are covered. The coils form, 

 therefore, together a more broadly rounded figure, which, however, 

 is not quite regular because the spiral is more flattened just opposite 

 the tip of the caecum. In the older foetus and in the adult, as is 

 mentioned above, there are three centripetal and two and a half cen- 

 trifugal central coils, in the younger one (h.) again there are three and a 

 half centripetal and almost three centrifugal central coils. This indicates 

 that by assuming the definite arrangement half a colic coil in either 

 direction is reduced. It may therefore be supposed that the ancestors 

 of Cephalophus ogilbyi has had the large intestine more spirally coiled 



