28 srnEiMA. 



very liltli- (loiii llin ifii?ifall oiviiiririi.' in tin- roiirsc r>f Hm- yi-ar in tin* (•(iin^sp^iiiliiii.' parts ol" 

 Eiiropfs'iii Russia, IRO iiiiiiiificiivs. Oiilv a Jaii/rT propdilifni than in Enidpcan Hn^sia falls in 

 the siiiniiirr nidiitjis, naiiii'ly 2L'() iiiilliiiP'ircs, the avrra^'i- lor Knr<ip<;an Russia br-in^ 190. 



]'"iMally, vi'iy variims arc llic cliniatic conditions pn'scritfil liy tlic polar t ii ml r a 

 /.((lie, of wlik'li nnlorlnnati^ly \vc aif in a position to jnd^'r almost oxclnsivfly from tlio ob- 

 servations taki'n on tin' siiiitlnTn liuril<'i- of ilic /ono at Rcriozov, Jtnlpinf? from llioso obspr- 

 vations till' MM'an anniiMl tciii|ii'i;itiiii' Falls lii-ro as low as — 5", antl fvcn lowor, tlic soil at 

 ii ticptli of lliri'r-(|narl('rs in oiii' aisliiiif lu'infr porpotually frozen. Tin- winter tomperatnre is 

 lower than — 21", that of the eoldest month, below — 23", while tlii; snmmer ttmiperature does 

 not exceed 4- i;5". 5, and thai id' the hottest month, -j- 18", formin;/ a dilToronoo botwoon Slimmer 

 and winter of 34", and b(3tweeii the hottest and cohlost months, of 49° Celsius, In Reriozov the 

 nieaii lemperntnre oi' the live-mnntli vogelath^e period scarcely oxceods 9°. and it is there- 

 I'me iiilelliLijhle iliiit the riveis are here ice lioniid i'uity days lonf2:er than on tin' rioiiiii-r of the 

 forest and afj;riciiltiiral zones, that the cereals arc ([iiitc^ incapable of growing and that the forests 

 attain the exti'cine range of their existence. Domestic animals also reach their limit in the 

 polar tiiiidia zone, with the exeepiinn nf the reindeer, which is peculiar to the tundras of 

 this zone. To the iioitli nf Uerinznv. beyond the aictic circle, the rainfall also decreases: in 

 Ohdorsk thi^ annual aiiiniiiiT is nnly 218 inillinieties. while in Beriuznv it is as ranch as 407 

 millimetres. 



The I'liiiiatic rdiidiiiiins of a cnuntiy appeal- most clearly and directly expressed 

 in its veiietable covering. It follows IViini iIh' aliove explained climatic conditions that the 

 herbaceous vegetation of the Western Siberia lowland differs very little from the flora of the 

 corresponding zones of European Russia, the more so that the comparatively low range of 

 the Ural is no barriei- to the disseiniiuilioii of plants whose seeds are freely htniw liillni- and 

 tliitliei- by the wind over the vast plains adjacent to either side of the mountain range and 

 lighting upon analogous conditions are sown and i-eproiliice their kind without let or liindrtince. 

 The traveller entering- Siberia tlirouaii ]''katerinl)nrL;- or Zlatoust, crossing the wliuji' Siberian 

 plain as far as Tomsk and further to the Yenissei. is not struck with any difference in the 

 herbaceous vegetation, but very few western species disappear, at times changing to eastern 

 varieties, as for example, the pale yellow heads of the European crow's-foot (troUius euro- 

 peus ],.) ail' replaced by the liery orange of its Asiatic variety (trollius asiaticns L.). Only 

 very few oriental forms appear not occurring in European Russia, or only here and there cross- 

 ing its frontier, as for example, some anemones (anemone reflexa Steph., altaica Fisch. and 

 pennsylvanica L), one beautiful species of paeony (paeonia anoraala L), a few crnciferae 

 (dentaria teniiifolia Led, chorispora sibirica, D.C., hesperis aprica poir), one species of \1olet 

 (violla iiniflora), araonir the.caryophyllaceae, lychnis sibirica L, among the compositae, a few 

 species of wormwood (artemisia desertorura Spr., turczanoviana Bess; macrantha Led 

 latifolia Led), the eastern forms of gentians (gentiana auriculata, Pall., aquatica L, 

 halenia sibirica Rorkh), et cetera. But the general character of the herbaceous flora remains, 

 the same. llit> plants merely becoming somewhat more sappy and fresh, and the flowers brighter 

 coloured than in European Russia, It is different with the trees upon which not the mean 

 temperature of the vegetative period aloue, almost constant on that side of the Lral, exerts 



