EACH IS OFFERED for one copy of THE 
AMERICAN NATURALIST for December, 1888, 
and for December, 1891. 
LOCKBOX 2, WILLIAMSTOWN, MASS. 
MARINE BIOLOGICAL SUPPLY DEPARTMENT 
Preserved material of à ae of Seige toe de class 
work or for the pri 
and all tdermanoit address 
GEO. M. GRAY, CURATOR - - WOODS HOLL, Mass. 
PES enS MICROSCOPES 
of mi size, style and price, suited 
or all kinds of work. 
A new series of lenses 
for dissecting work have 
recently been perfected by 
us which have unusually 
long working distance and 
Lens Holder for Anatomical Work. lenses are offered at 
prices less than any lenses of equal quality heretofore 
in use. The new Dissecting Stands are all nickeled - 
metal with glass stage. 1 Catalog free. ee 
Sample copy JOURNAL OF APPLIED MICROSCOPY on request. 
BAUSCH & LOMB OPTICAL CO. 
oed YORK OFFICE: CHICAGO OFFICE: dro 
Btreet and Broadway, Roe e We State and Washington Btreeta, d 
Townsend Bldg. N. Y — Seas 
THE ONLY MACHINE i 
all the gerrei rex ego time "y the simple touching E 
of keys, and noth = 
The only machine ever ever ire irran which multiplies ee 
and divi idis bey a matic keys. Ses 
accountant. No lever operate. hing to do 
to be spent on nbl cus computing when geome E 
. the work m De Cm f much less time p 
with absolute accuracy n 
[e Write for Pamphlet 
FELT ô TARRANT MFG. co. 
58 to 56 Illinois Street, 0 or t o n (CHICAGO, V.S.A. = 
large flat field. These ~ 
The only machine ever invented which will add 5 
but tou memini cm "Simple ight du Se ee der 
