360 University of California Publications in Zoology. (VouU-9 
tides are of minor extent but of some floral importance. These 
denuded and newly made areas exhibit plant succession in all 
its stages. The succession taking place on hillsides is somewhat 
different from that occurring on sand-spits and along streams. 
The usual suecession taking place on land slides in forest 
areas consists first of a growth of ferns (Athyrium) and a few 
herbs. Later Rubus spectabilis, Ribes bracteosum, and Vacci- 
nium ovalifolium invade the slide, and these in turn are replaced 
by Alnus sitchensis. This large shrub or tree holds the ground 
for years until replaced by the slow immigration of conifers. 
The riparian succession consists of more species and stages. 
This suecession usually runs from a beginning of Hpilobium and 
Lupinus through Salix and Alnus, then Populus, and finally 
Picea. Varying conditions of soil and moisture change this sue- 
cession somewhat, the conditions sometimes being unfavorable 
to some of the stages. 
The affinities of the flora of the Prince William Sound dis- 
trict are clearly with the coast region to the southeast through 
which most of the species range still farther southward. Only 
a small percentage of the plants range northward or extend to 
the adjacent Asiatic coast. The few species of mammals which 
reach the region have apparently a southeastern derivation, 
although their affinities are rather with northern forms. Ursus 
dalli and the forms of Microtus appear to be of Asiatie deri- 
vation. 
