DECEMBER 31, 1897.] 
are not shut up to this conclusion. There 
are various other ways in which pebbles 
might be introduced into eolian sand. The 
burrowing animals and the growth and 
decay of the roots of trees might introduce 
relics and stones from the top, if they were 
left by men on the surface. Relics of mod- 
ern civilization, bits of coal, pieces of brick, 
ete., were found in the sand down to a 
maximum depth of seventeen inches. The 
uprooting of considerable trees might bring 
up gravel stones of considerable size from 
depths of several feet into the surface ma- 
terial. If forest trees were ever upturned 
by winds in this locality they could 
not fail to bring up pebbles into the 
sand above the gravel. The breaks in 
the streaks already referred to might 
find explanation in such disturbances. 
In view of these possibilities the pres- 
ence of the pebbles in the sand cannot 
be asserted to prove that it is not of wind 
origin.* Finally, it is believed that no un- 
qualified conclusion concerning the origin 
of the relic-bearing sand is warranted. It 
may be of aqueous origin, dating from the 
close of the last glacial epoch ; it may be of 
aqueous origin of later age, for sea water 
probably covered the region at the close of 
the last glacial epoch or later; and it may 
be eolian, dating from a time long subse- 
quent to the deposition of the sand and 
gravel of the plain. 
Whatever its origin, it may safely be said 
that the surface material down to the lowest 
depth at which the relics have been found 
has been so disarranged that no affirmation 
can be made concerning the origin of the 
pebbles and relics it contains. It is all 
within the zone of active weathering and 
surface disturbance. If the finds were 
*My co-laborer in New Jersey, Mr. George N. 
Knapp, visited the locality where the relics are 
found in June; and reached the conclusion that the 
sands in question are eolian. No one else has more 
intimate familiarity with these sands than he. 
SCIENCE. 
981 
fossils, in the usual sense of the term, it is 
certain that geologists would not feel war- 
ranted in attaching much importance to 
them. 
Roti D. SALisBury. 
UNIVERSITY OF CHICAGO. 
SANARELLI’S WORK UPON YELLOW FEVER. 
AT the request of the editor of Scrence I 
append a brief résumé of Sanarelli’s re- 
cent papers upon yellow fever.* 
The mostimportaut study of yellow fever 
that appeared before Sanarelli’s investiga- 
tions were undertaken was that made in 
1888-9 by Dr. Sternberg, whose researches 
led to an essentially negative result. Upon 
only one microorganism found by him in 
the course of his thoroughgoing investiga- 
tions did any degree of suspicion fall, and 
the evidence against this germ was summed 
up by Sternberg as follows: 
“ Among the facultative anaérobics is 
one—my Bacillus X—which has been iso- 
lated by the culture method in a consider- 
able number of cases and may have been 
present in all. This bacillus has not been 
encountered in the comparative experiments 
made. It is very pathogenic for rabbits 
when injected into the cavity of the ab- 
domen. 
“Tt is possible that this bacillus is con- 
cerned in the etiology of yellow fever, but 
no satisfactory evidence that this is the case 
bas been obtained by experiments on the 
lower animals, and it has not been found in 
such numbers as to warrant the inference 
that it is the veritable infectious agent. 
“ All other microorganisms obtained in 
pure cultures from yellow fever cadavers 
appear to be excluded, either by having 
been identified with known species, or by 
having been found in comparative researches 
made outside of the area of yellow fever 
prevalence, or by the fact that they have 
* Annales de |’ Institut Pasteur, June, September, 
October, 1897. 
