Personal mid Scientijic Neivs. 63 
The placee mines about Downieville, on the Yuba river, 
had the reputation in 1851 '52, of being among the richest in 
California. Not only the "flats" along the banks, but the bed 
of the river and of each small tributary were mined, and every 
foot of bed-rock Avas searched over for the precious metal. 
After a lapse of more than thirty years we find companies of 
Chinese washing over the old gravels and obtaining from 
American waste sufficient to satisfy all the conceptions of 
Chinese wealth. A white man whom we found washing over 
old gravels in the solitude of Slug Canon, reported that from 
April to July he had obtained, in gold, an average of four dol- 
lars a day. When the gravels were first worked it was not un- 
usual to take out an average of $150 to $200 a day for each 
man employed. 
The Association of Western Naturalists held its first 
regular annual meeting October 24th and 25th, at Champaign, 
Illinois. About thirty members were present, embracing rep- 
resentatives from Michigan, Ohio, Indiana, Wisconsin, Illinois 
Iowa. Papers on methods of observation, and methods of 
teaching in geology were presented by T. C. Chamberlin, Presi- 
dent of the State University of Wisconsin, and S. Calvin of the 
University of Iowa. T. C. Chamberlin was elected president 
of the Association for the next year. Madison, Wisconsin, was 
chosen as the next place of meeting. 
Dr. Treub, director of the government botanical gar- 
dens, in Java, has recently visited the volcanic island, of Kra- 
katoa, and finds it covered with verdure from shore line to sum- 
mit. The significance of this fact will be appreciated when it 
is remembered that during the terrific explosions of the volcano 
a few years ago the heat generated w^as sufficient to destroy 
all the vegetation on this island and all the adjacent islands for 
a radius of several miles. The plants that first established 
themselves on the old cinder heaps and restored the beauty of 
waving foliage to the once desolate island, are, curiously enough, 
ferns. The ferns however, seem to have been preceded by cyan- 
op pyceous algae, which spread as a thin film over the surface 
of the moist rocks and cinders, and furnished the necessary 
conditions under which fern spores might germinate and the 
prothallus stage be safely passed. Without the algffiit is doubt- 
ful whether the ferns could have gained a foothold. Phaenog- 
amous plants are gradually getting possession of stations a- 
long ths shore, and they will in time, in part at least, displace 
the ferns. Geologists will be reminded by all this of the man- 
ner in which the pahieozoic continents received their flora. 
Ferns and their allies were the first occupants, and for a long 
time there was nothing but the fern-like forms. Was some 
low, creeping alga of which traces have not yet been detected, 
a necessary precursor of the palaeozoic ferns ? 
