NEW ZEALAND. 439 
middle island, on the southern coast of the northern island in Cook’s 
Straits, in the Bay of Thames, at Wanganui on the west coast, and 
elsewhere. 
Owing to the prevalence of the argillaceous rock, the country of 
New Zealand about the Bay of Islands is covered with a poor soil of a 
hard clayey nature, producing but little without great labour. And | 
was informed by the Rev. Mr. Williams that the same was the gene- 
ral character of the northern island even to its southern extremity. 
There are, however, volcanic tracts, which, though small, afford a 
rich soil, strongly contrasting with the unproductive clays. There is 
no natural pasture-land in the group, and this has been a great ob- 
stacle to the introduction of horses and cattle. Where the forests are 
cleared away, the fern springs up, and covers thickly the land. Both 
common and sweet potatoes are grown by the natives, and these, with 
Indian corn, have been their main dependence for food. 
Vicimty of the Bay of Islands.—The arenaceo-argillaceous rock 
of the Bay of Islands is singularly compact, seldom showing any 
appearance of lamination or stratification. It is fine in texture, or 
almost impalpable, with no traces of pebbles or even coarse sand. The 
general colour is grayish-yellow, passing into grayish-brown. It is 
rather soft, but is intersected, in many places, by veins which are 
more siliceous and hard, and more or less ferruginous; and these 
veins are often so numerous as to cut up the rock into small irregular 
blocks. ‘The blocks readily separate, and show that the veins are 
properly lines of fracture, and that they owe their appearance and 
character to a silico-ferruginous solution, which hardened the walls 
either side. 
This arenaceo-argillaceous rock passes into an extremely hard, 
siliceous rock, apparently of the same constitution as the softer variety. 
These siliceous portions do not constitute distinct layers, alternating 
with others that are soft; on the contrary they are local, arising seem- 
ingly from an alteration of the other rock, and graduating into it late- 
rally, instead of vertically. They cover, however, large areas, and 
are prominent in producing the peculiarly rugged scenery of the 
coast. Seams or veins of pure quartz are numerous. 
The general colour of the siliceous cliffs is a dirt-brown or grayish- 
black ; sometimes, however, it presents a dirty white, grayish-blue or 
pale flesh-red colour. ‘These varieties may be seen on the shores of 
the harbours of Parua and Tipuna. At the latter locality, the rock 
contains layers of red and brown chert, and also nodules one to six 
