Cockayne. — Botanical Excursion to Southern Islands. 269 



tective covering of snow subjects these plants to comparatively 

 severe conditions — much more severe, in fact, than any to 

 which the plants of lower levels are exposed. x\s for rain, 

 really heavy rain — according to Mr. Gordon — is not very fre- 

 quent ; usually it is a fine drizzle. In short, there must be a 

 great number of rainy days, but no excessive annual rainfall. 



GEOLOGY. 



x\ccording to Hector (40, p. 737), Campbell Island is a 

 volcanic mass, but has the peculiar feature of having, slightly 

 above sea-level, the original rock-formation on which it is 

 founded. On the north and south it presents fantastic peaks 

 and precipices carved out of rocks of the same character as 

 those which form Otago Peninsula. Towards the southern 

 end it is traversed by Perseverance Harbour east and west, 

 which is by a moderately high saddle connected with West 

 Harbour. On the north and south of this rift are frowning 

 clifi's and peaks of basaltic lava-sheets ; but at the sea-level 

 there is an exposure, both on the east and west coasts of the 

 island, of the Upper Cretaceous rocks, with chalk flints and 

 fossil wood, such as is found in New Zealand in the Upper 

 Amuri series. • These have been brought to the surface-level 

 together with the volcanic outburst, as thej' are injected and 

 interstratified with dykes and tufa rocks of the same kind. 

 The wonderful mystery of the occurrence of fossilised dicotyle- 

 donous wood in the far south latitude of Campbell Island is 

 therefore thrown entirely out of the distribution of plant-life 

 in Tertiary times, and must be referred to the Cretaceous 

 epoch. At an altitude of 800 ft. clear evidence of the existence 

 of a true corrie and moraine of the first order was obtained, 

 but it is purely local, and is the only evidence of former glacier- 

 action observed. 



According to Filhol (35a, p. 261), Campbell Island is 

 formed of a band of limestone and lavas. " The limestone 

 band is jammed between two coral dykes, the overflow from 

 which has partly covered it. This layer, the thickness of 

 which is about 70 metres, has evidently been formed in a very 

 deep sea. Fossils are absolutely wanting in it, and micro- 

 graphic sections have only enabled me to note the presence of 

 G-lobigerina. This limestone, which is of a yellowish colour, is 

 not met with again in any part of New Zealand. Its upper 

 surface at those parts where it is not covered by the lava is 

 not overlaid by any terrestrial deposit." " it is perfectly certain 

 that the geological age of the island, constituted as we now 

 see it, corresponds to the epoch of the appearance of the 

 volcanic eruptions." "The limestone which the eruptions of 

 Campbell Island have brought up, or which perhaps by its 

 fracture has formed a passage for the lava, must have been 



