22 Armitagb, Plant, Remains in Olivine- Basalt. [^''^Vun^^'* 



had been broken in consequence of the shrinkage undergone, at 

 the instant of cooling, by the material of which they were com- 

 posed. The fragments of these, often very numerous, lay around 

 the tree which they had before ensheathed. When these layers 

 had become tlius broken into fragments, the trunks which they 

 had surrounded, being left bare, had been grooved and scarred 

 by the rough scoriaceous blocks at the surface of the lava, and in 

 the direction of the current and the slope of its surface. It is 

 these casings which I have just described that certainly have 

 shielded the trunks from the effects of the incandescent liquid 

 that flowed all around. The greater number of the trees that 

 have been thus clothed with a protective covering are little 

 changed for the worse. As a rule, the bark only is destroyed. 

 A certain number of them have experienced a commencement of 

 carbonization of the woody part of their stems, but this decom- 

 position is rarely deep, and, by way of compensation, there are 

 some whose bark is so little damaged that certainly they will 

 survive the action of the bath of lava into which they have been 

 plunged." 



Mr. Guillemard (3), in describing in 1886 a volcanic crater 

 (Verbrandte Hoek) in North Celebes, to which he had paid a 

 visit, writes : — " It is a cone of ashes of regular sliape, whence a 

 small lava stream has issued, carving its way through the forest to 

 the sea. That it is of quite recent date is evident, for the ashes 

 and lava are devoid of all vegetation save a few patches of coarse 

 grass. Visiting it, we found that burnt trees were in many 

 instances still standing in the lava stream, so charred at the base 

 of the trunk that we could easily push diem down." 



Mr. Dana (4), in his work on volcanoes, writing on volcanic 

 phenomena in the history of the volcano Kilauea, in the Sand- 

 wich Islands, states : — " The lava sometimes, as in other 

 eruptions, flowed round stumps of trees ; and, as the tree was 

 gradually consumed, it left a deep cylindrical hole, either empty 

 or filled with charcoal. Toward the margin of the stream these 

 stump-holes were innumerable ; and in many instances the fallen 

 top lay near by, dead but not burned. . . The rapidity 



with which lava cools is still more remarkably shown in the fact 

 that it was found sometimes hanging in stalactites from the 

 branches of trees ; and, although so fluid when thrown off" from 

 the stream as to clasp the branch, the heat had barelv scorched 

 the bark." 



In another part of the book he says : — " Half-charred trunks 

 were standing, in 1887, with a rough cylindrical encasement of 

 lava about the stumps, projecting from two to two and a half feet 

 or more above the level of the solidified stream." In the book is 

 given a wood-cut of this phenomenon. 



Mr. Shaler (5), in a paper written in 1891, includes a plate 

 which gives a representation of the " margin of a lava stream 

 overflowing a soil occupied by vegetation." 



