Voyages of Discovery and Survey. 323 



months, due allowance being made for an ice-covering, these animals 

 would appear exposed to very moderate changes of temperature. 

 The marine creatures mentioned as obtained from the depth of 6000 

 feet wei-e within the range of uniform temperature (39 ■ 5), and 

 therefore would not be exposed to any change in that respect. 



The existence of live corals and molluscs at these depths in the 

 cold reoions of the (jlobe, beyond the range where life, based on the 



O O ' ./ O •II" 



consumption of terrestrial plants, is found, has a geological bearing 

 of much value, since we might infer that no part of the sea-bottom, 

 viewing the subject as a whole, is deprived of animal life. It might 

 as well extend to the south pole as to the latitude of the seas visited 

 off Victoria Land, if the depths be not so considerable as to inter- 

 fere with its existence by a pressure too great, or by an absence of 

 vegetable food upon which the marine life is based. 



While corals abstract carbonate of lime from the sources around, 

 and add, after death, to the sea-bottom by the accumulation of their 

 harder and calcareous parts, a multitude of infusoria obtain and 

 accumulate silica in the same manner. They not only appear to 

 swarm in the muddy bottoms off Victoria Land, but were also seen 

 in such numbers on the pack ice itself as to stain it of a yellowish 

 tint. Thus in these remote and desolate regions, as regards terres- 

 trial vegetation and the animal life feeding upon it, where the ordi- 

 nary decomposing and degrading effects of atmospheric influences are 

 checked, and to a certain extent unfelt, no running waters conveying 

 detritus or saline solutions to the sea, we find marine animal life busy 

 in obtaining and leaving solid carbonate of lime and silica. So that 

 the forms given to these substances mingling with the inorganic 

 matter otherwise accumulating, here, as elsewhere, in the temperate 

 and tropical regions, records are preserved of the life now existing 

 on the face of the globe. 



Among the islands visited during this voyage, v stay was made 

 at Kergulen's Land, sufficiently long to permit a slight insight 

 into its geological structure. Though, like so many of the ocean 

 islands, it presents us with igneous products, we here find detrital 

 matter mingled with them, with coal also and fossil wood. Mr 

 M'Cormick describes basalt, columnar and horizontal, amygda- 

 loidal rocks, greenstones and porphyries, as also slates termed 

 arenaceous, with veins of basalt and hornstone traversing the igne- 

 ous rocks. We seem to have the latter so mingled with detrital 

 matter as to shew that the mass of the island may have been ele- 

 vated since the accumulations were effected, volcanic ashes having 

 assisted in forming with the ordinary detritus from greenstones, 

 porphyries, or other igneous rocks, the sedimentary deposits pointed 

 out. However this may be, we have coal and fossil wood in a loca- 

 lity where now the most scanty vegetation is alone found, leading Dr 

 Hooker, who accompanied the expedition, to remark, that the con- 

 ditions for the growth of plants must have been far more favourable 



