include those from Costa Rica, Colombia, Brazil, Ecua- 
dor, Chile and Uruguay (Tschirch and Stock, 1936). In 
none of these cases, however, has the geologic age been 
established nor has the plant source been indicated. The 
deposits of amber from Chiapas, Mexico, will be dis- 
cussed later in this paper. 
Other sporadic occurrences of amber have been re- 
ported, but an exhaustive review here is not intended. 
I want merely to attempt to show the status of botani- 
cal investigations of the better known or what might 
appear to be more botanically significant deposits. 
Batric AMBER 
Amber from the Baltic region varies in its physical and 
chemical properties, although most of the material is 
considered to be succinite. It varies in color from yel- 
low, typical amber-colored to black and from transparent 
to cloudy or bony-opaque. Hardness ranges from soft 
and brittle to that which permits scratching with a knife. 
Some of it melts at approximately 350° C; some car- 
bonizes without melting. Some is practically insoluble, 
whereas 20-30% of the other pieces may be dissolved in 
alcohol, chloroform or ether. On the basis of these dif- 
fering chemical and physical properties, and the absence 
of succinic acid, ambers other than succinite (beckerite, 
gedanite, stantienite, glessite and krantzite) have been 
described from the Baltic deposits. 
The Baltic amber occurs within a relatively restricted 
sequence of greenish glauconitic sands, a ‘‘blue earth”’ 
and lignites. Although amber occurs scattered through 
all of these beds, it is most concentrated in the blue earth 
at the base of the green sands. The blue earth layer varies 
from one to seven meters in thickness, and amber occurs 
here so plentifully that yields of several thousand kilo- 
grams were obtained from an area of ten square meters 
(242 | 
