MURPIIV : 
I’IvNCU'IXS 01' SOrTII OlCokOIA. 
1 1 
colony usually selects the suuuuits of the \viiid\', shelterless ridges for its 
home. Why should uiariue birds which lack altoje,'ether the power of 
flight, and which are at best iiidiffereut walkers, prefer to make the 
period of proiiag-atioii difficult for themselves by retreating- as far as 
])ossible from their only source of food? I'he (juestioii has alreadv been 
raised by Levick ( 1914) with reference to the o-reat colony of /d;;m.src//.v 
adclia; at Cape Adare, where many of the breeders climb to the bare cre.st 
of the ca])e and make their nests three hundred meters above sea level.* 
In the case of neither J\ papua at vSonth Georgia nor P. adclice at Cajie 
Adare can the factor of .self-]wotection offer a ,satisf>-ing ex])lanation, for 
both si')ecies have oidy a single terrestrial enemy, the .skua, to the ravages 
of wdiicli they are as sii.sceihible on the highlands as on the shore. Dr. 
Levick does not explain the fact, merely .saying that it is “the result of 
their love of climbing.” A consideration of the hi.storv of South 
(Georgia, however, may hel]-) in an inter]H'etation of the .strange iirstinct 
which drives j^engnins of the genera Pygoscdis and Piidyptes to nest 
among the hills. 
Although South Georgia is little larger than Long Island, X. Y., its 
glaciers are as mighty as those of .Spit/djergen, and there is am])le 
evidence that the i.sland was formerly completely buried b}- an ice-ca]v 
The interior, which rises to an altitude of more than two thousand 
meters, is no longer ice-clad, exce]ding on the ])eaks, but is covered with 
an everla.sting neve of the Alpine type. This consolidates at the .sources 
of all the valleys to form tongues of ice, most of which extend clear into 
the .sea, ending in abrn])t walls. .Since mo.st of the fiords have been 
carved out by former exten.sions of the valley glaciers, the coast is ahno.st 
beachle.ss, the few areas of low, flat land being terminal moraines or beds 
of moribund or extinct glaciers. Even now, with the fluctuating .seasons, 
the glaciers .sometimes advance their fronts and flanks over coirsiderable 
ground once abandoned. t It is ])robable, however, that glaciation is on 
the wane and that an a])preciable decline has taken place even .since the 
vi.sit of James Cook in 1775. Certainly Ca])tain Cook’s detailed account 
of nnmelting ice and the absence (T fresh-water .streams in midsummer 
does not accord with ]>re.sent conditions. 
From the foregoing data it ma_\- be a.ssnmed that during a long period 
* The same trait is c<iually well illustrated at Macquarie Island hy one or more species of 
crested penguins (I-'.miyptrs) , a preliminary account of which is given in Mawson's I'hr Home of the 
Blizzard, Toiidon, 1915. 
t Cf. Murphy, R. C. lYtermannf Mitteil., Ootha, Vol. 'lo, Kp.p (Mai-IIelt) p. 2S0. 
