Ko. 479] EXTINCTION OF MAMMALIA 



779 



In a paper entitled "Das allnialiliclio Ausstorhen des Wiseiits 

 (Bison bonasm Linn.) ini Forstc vo.i Hjelowjesha",' Mr. Kn.iren 

 Bueliner gives a detailed liistory of the l)i.s(')n herd in the Hie- 

 loviejsha (or Uialowitza) forest, Province of (Inxhio, in I.itlniain'a, 

 Russia, durin<!^ the })resent eenturv. "A careful stndv of the 

 breeding habits of the bison in the Hieloviejsha fonvst and cl.se- 

 where leaves no room for donbt that tlie j)resent slow rate of 

 reproduction is an abnormal condition, and that to it is due the 

 rapid approach of the extinction which is the certain fate of the 

 herd under consideration. This diminished f(Mlility the author 

 regards as a stigma of degeneration c-aused by in-breeding. . . . 

 Another indication of the degenerate condition of the Bieloviejsha 

 herd is seen in the great excess of bulls, which j)robably outiumiber 

 the cows two to one. This is doubtless a result of in-breeding, 

 for Diising {Jen. Zriis. j. Xafiinr., Hd. xvii, ]). 827, bS84) has 

 shown that close in-bre(Mling, like a reduced condition of nutrition, 

 is favorable to the production of an excess of males.... In con- 

 clu.sion, the author considers that lu's studies of the history of the 

 Bieloviej.sha bison leave scarcely room for doubi thai in-brccdiiig 



breeding must begin and lead gradually bin ccrlainly to the e.\- 



reduced in numbers as to be s(>paratcd iiuo isolaicil colonics." 



hiflwncr of Cold dunn.j thr Urpn>d nrfnm l\rlnd.- Kxrcptional 

 old xxavc. or unu..ia!b prolon-e.! cold .ca^.n^ ma^ cau.e a 

 hMnp,.rary lo.^ of f.m.l Supply or can^e the death of the young, 

 which hi northern latitudes " are usually born in spring." The 



of a series of destructive ellVcts of a progre.s.sive .secular change. 

 These may be Munniari/ed as follows from actual :onl<>ui,al 

 observations' among the Cervida': ia) disturbed conditions dur- 



(througli hunger) condition of females durinu' [)arluritinii period; 



