OF MONTE SOMMA AND VESUVIUS. 111 
the valloni is the more or less deep incision or ‘‘cupa’’(as locally called) 
which furrows them along their spine. These cupe are often of 
considerable depth, occasionally as much as 20 metres, and have 
almost perpendicular walls. Their origin in all cases seems to be 
the result of human agency. As they play an important part in 
odi fying the superficial form of the mountain, a few remarks 
a propos of the manner in which they are produced will be necessary. 
Fig. 2.—Section in the Vallone St. Patrizio, about the 550-metre 
contour-line on the right side in ascending. 
“a 
SEK WG See 
SNe <= (AIS SE IGEN 
Soe 
SS \ — « 
a. Alluvial breccia, sand, &c. = Puasxs VII. and VITI. 
6. Pumice of Puss VI., Period 4. 
e. Yellow earthy ash, with fragments of pumice=Puass VI., Periods 2 and 3. 
d. Compact grey pumice and lapilli = Puasn VI., Period 1. 
d’. Vegetable soil = Puasss V., IV., and III., Period 4. 
é. Regularly stratified rounded lapilli and sand of different sizes, with a 
few fragments of black spongy pumiceous scoria, Puase ITI., Period 3. 
f. Black compact pumiceous scoria = Puase IIL., Period 2. 
g. Light and white pumice = Puass III., Period 1. 
h, Ancient lava = Puass I. 
This section is intended to show the erosion of one bed before the deposition 
of another. 
Above the 300- or 400-metre contour-line the two chief vegetable 
products of Monte Somma are chestnut trees and bushes and an under- 
growth of two or three species of broom or Gensta. The first of 
these supply sapling poles, brushwood, and charcoal ; the second brush- 
wood only. The mountaineers occupied in the collection of these 
products make both the ascent and descent of the mountain along 
the ridges instead of the valley-bottoms. As the latter are rough 
and jagged from the lava-beds, and intercepted from time to time by 
