loo LIFE : OUTLINES OF GENERAL BIOLOGY 



and perhaps a dozen fall into hibernation, the majority have to 

 trek soutliwards before the snows and storms. We can picture the 

 march of tlie deer, with the wolves and gluttons at their heels. 



Thi- Mammals oi riii-: Steppes.— Let us continue our attempt 

 to envisage animals in relation to their characteristic haunts; 

 the animal life of the Polar regions, the tundra, the northern 

 forests, tlio mountains, the desert, the tropical jungle, and so 

 on. The most striking book on the subject is Miss Haviland's 

 Forest, Steppe, and Tundra: a Study in Aninial Environment 

 (i()2()); and we wish just now to think about the mammalian fauna 

 of the Steppes. 



By a "steppe" is meant a great tract of undulating grass country, 

 "a sea of herbage", and it includes "prairies" and "pampas". One 

 of the most characteristic, often called the steppe, extends east- 

 wards, in Russia and Siberia, from the plains of Hungary to the 

 foot of the Altai Mountains. Many of us have visited this tract of 

 country under the enchanting guidance of Aksakoff and Tchekov; 

 and we are always ready to go back, for there is a peculiar fascination 

 in the steppe. 



In her admirable book, Miss Haviland points out that the two 

 outstanding physical characteristics are "the fierce extremes of the 

 climate and the monotony of the landscape". The summer tempera- 

 ture may be like Morocco, the winter like Novaya Zemlya. There is 

 heavy rainfall in spring, parching drought in summer, desiccating 

 wind and keen frost in winter. These conditions favour grass and 

 certain kinds of wiry herbage; they make it difiicult for trees to 

 live, except in sheltered depressions beside rivers and lakes. In May 

 and June the steppe is a garden of mulleins, mallows, larkspurs, 

 romjwsites, vetches. "In July the flowers fade, the grass scorches 

 brown, and the steppe appears like a parched stubble field." In 

 winter the biting wind sweeps up the snow except from the hollows; 

 and death stalks over a bare land. 



The second characteristic of the steppe is the monotony. It is an 

 open plain, with great rivers, no doubt, but scarcely broken by 

 hills an environment, as Miss Haviland says, that has nurtured 

 thinkers and dreamers, just as the fierce extremes of the climate 

 have prompted explorers, adventurers, warriors, and nomads. How 

 does this apply to the mammals? 



In a grassland one expects many herbivores in other words, 

 many rodents and ungulates. But the number of possible inhabitants 

 of this type is greatly reduced by the lack of shelter, by the often 

 torrid summer with a baking sun, and by the often frigid winter 

 with its bitter winds. One line of survival is swift trekking; another 

 is burrowing. Let us take the second first, with Spalax as type. 

 It is a vole adapted to the underworld like a mole. But Spalax is 



