120 EINAR LONNBERG, MAMMALS COLLECTED BY THE SWEDISH ZOOLOGICAL EXPEDITION BTC. 
numerous in certain localities as well as on the southern side of the river below 
Chanler Falls. In the dry country there numerous game paths lead to the river, and 
in the dust of these paths the spoors of Rhinoceroses were a regular feature. Probably 
many of these paths were just the products of the more or less regular walk of the 
Rhinos between their pasture-lands and the water. In day-time the Rhinoceroses are 
very seldom found near the river. As a rule they are met with at a distance of 
from 5 to 8 kilometres, perhaps more, from the water. Their chief food appeared 
to be a low scrub. They were found not only on the flat country but sometimes 
on the mountain slopes in the bush among rocks and boulders where one hardly 
could imagine that such a bulky and clumsy-looking animal would be able to find 
its way. 
Here and there along the paths of these animals such places are seen where 
they are used to deposit their droppings and then scatter them. Such places are 
usually situated at a bush which as a rule has been broken and kicked to pieces, 
and a big hole is scooped up in the ground. It is sometimes stated in the literature 
that the scattering of the dung is done with the horn. Although I never have seen 
a Rhino at work it appears to me quite clear that at least most of it is done with 
the feet to judge from the deep furrows radiating from the hole and which exactly 
fit to the breadth of feet and in which even toe marks may be seen. 
It is very difficult to explain how such a habit could have originated and be- 
come fixed, for it can impossibly be in any way useful to the animal now and thus 
be explained by natural selection. It might, however, be an inheritance. 
The propagation of the Rhinoceros is, of course, slow, as usually is the case 
with such big animals, and it takes a long time before they reach full development. 
The fact that female Rhinoceroses often were seen in company with their not far 
from fullgrown young proves that several years pass between each period of gravidity, 
or parturition. On the other hand it is evident that the female Rhinoceroses in the 
districts visited do not suffer from barrenness because as a rule they were accom- 
panied by a more or less grown up young. Sexual maturity is reached before the 
last molar has cut the gum as can be concluded from the fact that this tooth was 
not fully developed in a female which Mr. Ss6GREN shot south of Guaso Nyiri and 
which was followed by a good sized calf. On the other hand, a male Rhinoceros 
(Pl. VII, fig. 2) with only six cheek-teeth in use had comparatively very small testicles 
in which no ripe sperms were found, and it was thus not yet sexually mature. This 
animal measured from snout to vent in a straight line about 255 em. (about 8*/s 
English feet) or 295 em. along the dorsal line. Its exact age is difficult to tell but 
it was probably several years old. It had like all other Rhinoceroses observed at 
close quarters numerous scars and ulcers (conf. the fig.) along the flanks. If those 
are obtained when the animals fight inter se or not is impossible to say, but it is 
most probable because hardly any other animal would dare to attack them, and the 
skin is too hard and thick to be deeply scratched by the thornbush, The Rhino- 
ceroses were found to be infested by ticks of the species Hyalomma cegyptium (L.), 
