X INTRODUCTION. 



interest to the results of the examination by Mr. Brady 

 of the foraminiferous deposits of the Western Pacific. 

 One of the most important results will be to establish the 

 great elevation which has occurred in this region during 

 Post-Tertiary times. We are therefore justified in regard- 

 ing the island groups of the Western Pacific as having 

 always retained their insular condition, situated, as they are, 

 in a region of upheaval, and separated, as they are, from 

 each other and from the Australian continent by depths of 

 +rom 1,000 to 2,400 fathoms. I have already pointed out 

 that the volcanic rocks of the large islands of the Solomon 

 Group are geologically ancient. Their elevation and the 

 great subaerial denudation which they have experienced 

 afford indications of the insular condition having been pre- 

 served from remote ages. It is this prolonged isolation that 

 explains the occurrence of the peculiar forms of the am- 

 phibia wliich I discovered in Bougainville Straits, and that 

 accounts for many of the peculiarities of the fauna of this 

 archipelago. 



Having thus briefly considered the leading geological and 

 liydrological features of this group, I pass on to consider 

 these islands in the point of view of an intending settler. 

 They are for the most part clothed with dense forest and 

 rank undergrowth, and it is only here and there, as in the 

 western portion of Guadalcauar and in limited localities in 

 St. Christoval, that the forest gives place to long grass and 

 ferns, a change often corresponding with the passage from a 

 clayey and calcareous to a dry porous and volcanic soil. 

 As a rule, the calcareous districts of a large island possess a 

 rich red argillaceous soil, often 5 or 6 feet in thickness, and 

 in such localities the streams are lar^e and numerous. In 

 the districts of volcanic formation the soil is drv, friable, 

 and porous, whilst the streams are few in number and of no 

 great size. In the principal island of the Shortlands the 

 difference in the character of the soil between the volcanic 

 north-west part and the remaining calcareous portion is well 

 exhibited. In the smaller islands the soil varies in character 

 according to the formation, those of volcanic origin being 

 singularly destitute of streams. 



\n chapter XVII. I luave divelt with some detail on the 

 climate. The healthiest portion of the group would, as I think, 

 be found in the eastern islands, and the healthiest part of each 

 island would be that which is exposed to the blast of the 

 south-east trade during a large portion of the year. The ex- 



