West Indian Volcanic Fonnafioiis. — Spencer. 51 
left in broken series. The newer gravel has not been sub- 
jected to so much denudation. The youthful lavas have been 
seen both in Dominigua and St. Kitts, beneath the stratified 
gravel beds at present not determined as to whether belonging 
to the older or newer series. The lower gravels in their 
succession correspond in position to the Lafayette of the con- 
tinent, and the upper gravels to that of the Columbia. The 
eruption which raised the cones in St. Kitts and Statia, above 
referred to, appears to have occurred during the subsidence 
which gave rise to the upper gravels provisionally regarded 
as the equivalent of the Columbian series, — a mid-Pleistocene 
formation — and the marl beds thus raised rest upon an inco- 
herent bed of volcanic ashes, containing living fauna. From 
all facts before the writer it seems that the volcanic ridges owe 
their origin tO' volcanic activity which re-commenced about 
the close of the Pliocene period, and that the eruptions have 
continued with more or less interruption down to the present 
day, for we find that the cones and ridges have not become so 
deeply dissected by rains and streams as would be expected 
had their growth not been continued more or less continu- 
ously from their re-birth at the close of the Pliocene period 
to the present year of recorded activity. 
EDITORIAL COiMMENT. 
THE DIAMOND MINES OF SOUTH AFRICA. 
Just how much of the popular interest in diamonds is due 
to their value and beauty for personal adornment and how 
much to the difficulties in the way of satisfactorily accounting 
for their origin, it is perhaps impossible to say. The true sci- 
entist would, undoubtedly, claim that with him the latter in- 
terests were paramount. Still, there exists in our minds a 
doubt if, were diamonds as cheap and abundant as quartz 
crystals, the interest, even of these, would be as intense. 
Be this as it may, from the earliest period when stones of 
high refractive index were faceted, the diamond and all relat- 
ing thereto has possessed a fascination for the general reader 
beyond that of all other gems. A recent work. "The Diamond 
Mines of South Africa" bv Gardner F. Williams (The ^lac- 
