96 DISTRIBUTION AND CENSUS. 



bright flame, and omits a smell by no means disagreeable. It is used 

 for ornamental purposes and for making amber varnish. Amber is the 

 product of coniferous trees which flourished in early Tertiary times, 

 probably of more than one species but which cannot be clearlv 

 determined. Pieces of amber have been found in which are preserved 

 entire the bodies of insects that inhabited the primeval forest formed 

 by these trees. 



Kauri Gum is a semi-fossilised deposit buried at a depth of 

 five or six feet below the surface of the ground in tracts of open 

 land in the northern island of New Zealand where once grew Kauri 

 forests ( Acjathis australis) which have long since disappeared. It is 

 sometimes found in large lumps but more frequently in fragments 

 varying in size from that of a hen's egg to that of a man's head ; 

 it varies also in colour, being sometimes of a rich brown, sometimes 

 bright amber-yellow and occasionally almost colourless and translucent, 

 revealing flies and small beetles that have been enclosed in it for ages. 

 The clearest and most crystalline pieces are most valued ; they are 

 carved into ornaments scarcely to be distinguished from amber, but much 

 more brittle ; the inferior kinds are manufactured into varnish.* 



A few other products only locally utilised are noticed under the 

 species from which they are derived. 



DISTRIBUTION AND CENSUS. 



THE present distribution of the TAXACE.E and CONIFERS over the globe 

 has resulted from the gradual geological changes that have been 

 effected since the first appearance of a coniferous vegetation in the 

 earlier formations of the Earth's crust ; and the existing genera 

 and species are believed to have been developed in the course of 

 ages from others that have long since become extinct. The evidence 

 adduced in support of this belief consists in the fossil remains of 

 plants (and animals) found in the different strata of which the crust 

 of the Earth is composed, and which are proved to have been laid 

 down slowly by the action of water. Et is further proved that the 

 distribution of land and water on the surface of the globe has not 

 always been precisely the same as it is now, areas which are now 

 dry land having been at one time covered by the sea, and vice versa, 

 and also that the changes in climate have been not less remarkable. 

 Similar formations and consequent changes are still in progress on 

 a vast scale in every region of the Earth, chiefly by the agency 

 of water as is seen by the deposits of layers of mud and silt 

 which are continually accumulating at the mouths of the great rivers, 

 as the Nile, Niger, Ganges, Yang-tse-Kiang, Mississippi, etc., and 



* Kirk, Forest Flora of New Zealand, p. 154. 



