THE GROWTH OF CONTINENTS. 
138 
in the neighborhood of Neufchatel, that the in- 
vestigations were made which first led to the 
recognition of the changes connected with the 
Periods. As I shall have occasion hereafter to 
enter into this subject more at length, I will only 
allude briefly here to the circumstances. In so 
doing I am anticipating the true geological order, 
because I must treat of the Jurassic and Creta- 
ceous deposits, which are still far in advance of us ; 
but as it was by the study of these deposits that 
the circumscription of the Periods, as I have de- 
fined them above, was first ascertained, I must 
allude to them in this connection. 
Facing the range of the Jura from the Lake of 
Neufchatel, there seems to be but one uninter- 
rupted slope by which it descends to the shore of 
the lake. It will, however, be noticed by the 
most careless observer that this slope is divided 
by the difference in vegetation into two strongly 
marked bands of color: the lower and more 
gradual descent being of a lighter green, while 
the upper portion is covered by the deeper 
hue of the forest-trees, the Beeches, Birches, Ma- 
ples, etc., above which come the Pines. When 
the vegetation is fully expanded, this marked 
division along the whole side of the range into 
two broad bands of green, the lighter below and 
the darker above, becomes very striking. The 
lighter band represents the cultivated portion of 
