TORTOISE. 399 
of the desert, as is to-day the horse of the Arabs and Berbers. The excellent 
observations of H. Kraemer* on the strength of the metacarpalia in the horse, 
taken together with well-known observations of the peculiar build of all animals 
of the desert, enable us to understand how there could occur a differentiation 
into slender-footed, slender-limbed, so-called Oriental horses on the one hand, 
and thick-footed, heavy, Occidental horses on the other hand. The differences 
in physiographic conditions were, in my opinion, the cause of the formation of 
both of the main groups of our horses. 
The wild ancestral form was the same for both; it was the Diluvial horse 
of the ancient world, which roamed as far as the loess steppes and tundra plains 
extended; and which, surviving in separate groups the disappearance of the 
tundras, was transformed, according to the newly developing regional physio- 
graphic influences, into the desert-type (Equus caballus pumpellir), the steppe- 
type (Equus caballus germanicus seu robustus), and the forest-type (Equus caballus 
nehringt). 
The same history is true of most of the domestic animals; and I do not 
hesitate to express the opinion that the change to slenderness in the hollow bones 
of the ox, together with the diminution of bodily size, as well as a general stunting 
(hindered development) in an early youthful stage of the normal form, developed 
gradually under the same influences, for it is evident that under conditions of 
insufficient food, early pairing and inbreeding—as to-day in Turkestan—the cattle 
were used for riding and driving, but not for milk and fattening. 
TORTOISE. 
Testudo horsfieldii Gray. 
Remains of the tortoise, consisting of dorsal and ventral plates, occur among 
the bones collected in Komorof's trench. They are, therefore, of an indeter- 
minable age, but the form of these well-preserved plate bones permits an exact 
determination of the species, Testudo horsfieldii Gray. 


* Zur Frage der Knochenstaerke der Pferde. Deutsch. landw. Tierzucht, 1904, Nos. 28 and 31. 
