Editorial Comment. 323 
masses have been described by Lawson, Williams and Winch- 
ell in the oldest greenstones, and they have been referred re- 
spectively by them, to "concretionary structure," to breccia- 
tion and subsequent rubbing under "dynamic pressure," and 
to "agglomeratic accumulation" under the surface of the 
cotemporary ocean, in the near vicinity of an active volcano. 
Two of these theories require a surface origination of the 
rock, from volcanoes, and the other demands a plutonic, or 
deepseated, intrusive origin. It appears that, with the facts 
that Mr. Ransome gives, the superficial origin of such forms 
is proved, and it remains to determine whether the sea were 
present to receive the ejected material or whether it was 
evenly and rather slowly ejected upon a land surface and sub- 
sequently flowed in such manner as to produce these forms. 
Without calling in question here the close "resemblance exist- 
ing between these forms and the forms to which they are 
compared in the volcanic rocks of the Hawaiian islands, we 
desire to mention some considerations that seem to point 
toward the cotemporaneity of the "spheroidal basalt" and the 
jaspers of the San Francisco sandstone, and thus also indi- 
cating oceanic conditions for the accumulation of both. 
1. The author considers that the San Francisco sandstone 
is separated into two parts, by the intervention of a bed of 
considerable thickness of jasper rock, called phthanite by 
Becker, showing that something affected the ocean in the vi- 
cinity of San Francisco bay which caused the rapid precipita- 
tion of silica, which at the same time was stained by a little 
iron. The author refers to various places, at a distance from 
San Francisco, where red jaspers also occur, saying "the rock 
[i. e., spheroidal basalt, N. H. W.] is always associated with 
the red jaspers, and with what is apparently the San Fran- 
cisco sandstone" (p. 110), admitting that this association in- 
dicates "a contemporaneous rather than a subsequent origin 
for the basalt," (p. 109.) 
2. The rock of the spheroidal basalt is found to contain, at 
least in one instance noted, blocks of sandstone four feet in 
diameter (p. 78) which shows that some force was in action 
which could rend and transport solid rock, and mingle the 
fragments with the spheroids. It may be questioned whether 
flowing lava could do it. Was the force volcanic explosion? 
