position. They were nuclei in a process of spheroidal weathering, and 
the intervening rock material has been split off, disintegrated and carried 
away by wind or rain and thus these rounded blocks were left lying 
upon the surface. Their stages of development are sometimes well ex- 
posed in road or stream euts. Their relation to the floor on which they 
rest is often shown by a vein or dike that cuts through the boulder and 
is continued in the bedrock at its base. 
In the summit region, dome forms are often produced, the form of 
the hills being determined by the curving joint planes in the granite 
rock, 
Even where the relief is moderate or low, a surprising number of 
bare rock surfaces are exposed. The products of disintegration must 
be washed, blown or slid away before plants can get a hold that might 
tie the slowly developing soil to the rock beneath. 
Most striking were the results of the heavy storms that affected 
the whole region last spring. The streams had made fresh and often 
deep cuts, and had exposed and moved great quantities of large rocks 
which normally they would but flow around. Landshde scars on the 
hillsides were common sights, and on the higher and steeper slopes, the 
similar bare strips cleared of their shght coating of vegetation (lichen 
and brush) by the rush of the rain waters gathered into steep and nar- 
row runways. 
In the low grade stream valleys of the summit region the detritus 
gathers from the mountain slopes and frequently carries considerable 
water—often more water under ground than in the stream bed. 
The biologists may be interested to note that in the struggle for 
existence under unfavorable arid conditions many of the streams be- 
come adapted to their environment, by developing a bed of gravel and 
sand through which the water may flow with a minimuin effect of evap- 
oration. The surface stream bed may to all appearances be dry and life- 
less while beneath the protective covering a goodly amount of water 
may be moving onward towards the sea. Naturally those streams which 
have the better adapted themselves, have a better chance of surviving 
through the dry season. 
Decomposition and the formation of soil is more marked in these 
valley bottoms. They are the favorable seats for trees and many fine 
large ones were observed in such situations. But on the hillsides that 
usually have little or no soil covering, and slight water conservation 
plants have a more precarious existence. 
A eross country excursion is valuable in giving one a picture of a 
region’s general features, geographic, geologic and biologic, in their 
