The sun. [volume] (New York [N.Y.]) 1833-1916, 1899-12-10

| indeed, II COnndent thnt inc Bflusn fauna Iur
nishes the key 10 the solution Of the problem Of
the origin Of many European animals II In certain
that the British species by land, at least the
bulk ofthem but whence came they. and al what
time did they arrive7 Another interesting ques.
ton Is, Al what date did Ireland become discon-
nectod from Great Britain, and tho latter from
Scandinavia and France2 Prof. Boyd Dawkins
has indicated the special line Of research which
should he followed " such inquiries are TO be an
swered. The absence" he says, "of the beaver
/ and dormpuse from Ireland must be duo 10 the
existence OF some barrier 10 their westward migra-
ton from the adjacent mainland, and the fact
that the Alpine hare Is Indigenous, while the
mon hare IL absent, implies that far as the
| former animal was concerned, the barrier did not
| exist" Another fact TO he noted IL that many
| members Of the great Siberian invasion reached
England but Ireland remained entirely free from
these migrants The assumption, consequently
seems reasonable that tho latter country at the
time Of their arrival was no longer Joined to Eng
! land The great bulk Of the Irish fauna Is com
/ posed Of Lustanan. Alpine an Oriental imlni-
grants, and there In. besides, q dictincty Arctic,
! or North American element All these. Of course.
must have established them selves in Ireland before
the Siberian fauna set foot In England. since II
/ has boon shown that n continuous land surface
was necessary for their mgrations Owing To
the perfect preservation Of the remain, Of tho
Siberian migrants in recent Continental deposits.
the history Of their migration can be closely fol.
lowed. and II Is possible even to determine the
date Of Its arrival in England, at any rate, in
geological language. The time OF the COLOMBIA.
ton Of Ireland thus can be fxcd approximately
as having taken place at a period prior TO tho
arrival OF the Siberian migrants in England.
All those who have seriously mined the prob
lens presented by tho British fauna. including
the late Prof Forbes and more lately. Mr.. Car
penter. az well az the author Of this book. are
agreed that the I.usitanian element il the Oldest.
and that the newest Is that which came to Britain
from the East The seq uence. then. Of events
in the British Islands was probably e. follows:
The first corners were the members Of that fauna
which issued from Southwestern Europe: then
came the Alpine. and, al the same time. probably,
the Arctic and the Oriental; and. finally the East.
tIn. or Siberian The mEratons NJ all but tho last
continued unin,errup'eily for very long periods
II.
by the study OF these mgra,ions, our ,uthor
has been convinced that. though climate was
a powerful factor in the evolution OF history OF
the European fauna, the geographical changes
which took place the European Continent
in later Tertiary times eHer,ed yet stronger in
iuence The principal climatic disturbance is
"Ice Age" Among naturalists Of the present
day, there Is a widespread and hrmly-roo,ed
belief that the Ice Age proved ~ destructive TO
European fauna that all animal life practically
disappeared from large areas Of the European
Continent For this reason, DR. Schard deems
IL desirable to review briefly In his introduction.
the history OF that remarkable p~riod. in order
10 ascertain how far this belief In corroboraied
by facts Throughout, this book moreover IRE
quent reference will be found to tho theories con-
nectcd with the Glacial period. II has been as.
serted for example, by an eminent gcologist
that during part OF the glacial period the climate
was such that neither plants nor animals could
have existed In the British Isands DR. Schard
points out that, II this had been o. very few or.
ganisms could have survived in France either
though number Of Arctic species might have
dragged on an existence In Southern Europe
Al any rate, on the return Of more genial cond.
tons. the Arctic species would undoubtedly have
beeu the nrr TO gain admission Ia the British
Islands, and TO re-p-ople the srid wastes our
authors supposition that the Lusitanian element
In the British fauna is the oldest would. there
fore. be wrong. From early Tertiary times on.
ward. tho climate Of Europe, which was then
e-mi.;ropical. gradually became more and more
temperate; until, finally, the Ice Age or Glacial
prioi arrived, during which, according to Prof
j. Geikie one Of the highest authorities on the
subject great part Of Northern EUROPE b~cams
practically uninhabitable. owing to the severity
OF the climate DR. Sch,rH surpcs,s thu, in
order to judrr better OF the resp,ctiy, value Of
IN. .eycr,l bvpoth.ses which h.v. hon advanced
10 accoun, for the supposed extraordinary fail
OF Temperature during IN. Ic. Az. ". should
compare the views Of many authorities n.
does not at,empt to discuss the cause, which lcd
TO tn. production Of IN. Glacial period hut merely
TO consider the climatic nspr,r, from , phy.,c,i
geological and botanic poin, of view
According IN Prof p.nck the nature n, IN.
Glacial climate ca be determined nv conp,rinr IN.
snow line Of the Glacial pertod with ,b,, n, toll,
The position Of the snow line IL de,end.nt m
two climatic tartors namely. precipi,,,iop and
,empera,ure We know IN, h.irh, a, which
snow must hay. lain permanently duri,g ~.
Glacial period, or during tho maximum nh,s.
a glaciation tn. Ice Ar. b,d h.,, p,oduc.d
SOLELY by nm i,cr.os. Of snow fall a, has h..n
serted, PROT. penck POINTS OIL, tina, then !, r,nst
have showed three or four times a, much as I,
DOES now He does no, rd,n, tho vi.x hn,,.,..,
that the Ice Age is due 10 AN increase n, srn.,,
fall nlon. His ,l,tio,s T., sed ,,,o, III. Bit,