82 PITTONIA. 
lower sides. In the larger of these ponds Nympheea is gener- _ 
ally found growing. These tracts appear to be the home of the 
Juncacee and Cyperaces, with a few of the Gramine:e, while 
their borders furnish representatives of many orders, such as 
Poterium medium, Leptarrhena pyrolifolia, Parnassia fim- 
briata, Cladothamnus pyroleeflorus, Gentiana Menziesii, Spi- 
ranthes Romanzoffiana, Veratrum, Scheuchzeria palustris, | 
etc. The soil is very firm, rich, and not excessively wet; 
therefore why they are entirely treeless, while surrounded 
by trees, I am unable to determine. 
LANDSLIDES usually occur in March, though I have seen 
one take place in May. They are from a few square yards 
to several acres in extent, and are caused by the water from 
the melting snow freezing in the rocky crevices at night and 
by expansion displacing the rock, which, once started, may 
carry hundreds of trees and thousands of tons of rock to the 
level ground below or, more frequently, into the sea, for 
most of them oceur near the seashore. Although previously 
covered with conifers, not a single conifer, as a rule, is to 
be found in the new growth, which consists of the two species 
of alder, an occasional vine maple, Rubus spectabilis, Ribes 
lacustre var. parvulum, Romanzoffia Sitchensis, Epilobium, 
Arabis, Campanula, Aquilegia, etc., together with a few Alpine 
waifs, such as Leptarrhena pyrolifolia, Parnassia fimbriata, 
Cassiope Mertensiana, Cassiope lycopodioides, Cladothamnus 
pyrolzflorus, Lycopodium alpinum, etc., all of which, how- 
ever, disappear in the course of a few years as the alders at- 
tain sufficient growth to crowd them out. One of these 
slides close by the sea, which I examined in 1890, contained 
the above six Alpine plants. On returning to it in 1895 the 
only one of these still holding its ground was Cladothamnus. " 
Leptarrhena and Cassiope Mertensiana were present, but no 
longer strong enough to flower, while the others had quite x 
disappeared. 
US TI Re Er SD PS b 
