ns 
characterization of ambers in terms of carbon, hydrogen 
and oxygen ratios, melting points, specific gravity, solu- 
bility in certain standard chemicals can be used in a gen- 
eral way to distinguish different fossil materials, but it 
does not permit comparison with modern resins, ‘Tests for 
the presence or absence of succinic acid also are of rela- 
tively little help, as many plants contain small amounts 
of succinic acid, but none are known to have as high a per- 
centage as occurs in succinite. [tis possible that this high 
percentage is due to post-depositional oxidation or, per- 
haps, to techniques of analysis such as dry distillation. 
Recent techniques, such as infra-red spectrophotometry 
and gas chromatography, hopefully may provide distine- 
tive patterns. Resinographic methods (Rockow, 1961), 
such as study of etch patterns or examination of natural, 
fractured or prepared surfaces of the whole material and 
of its separate phases by vertical reflected light are po- 
tentially valuable. Klectron microscopy on the level of 
discrete, giant macromolecules may produce additional 
useful information. Collections of resins from living pro- 
ducers are necessary to establish comparative spectra, 
chromatographs, micrographs, etc. .A survey of the de- 
scribed flora of Chiapas (Miranda, 1952-538) indicates 
possible sources not only among conifers but also among 
angiosperms (Howes, 1949). Among the conifers, there 
are numerous members of the Pinaceae, several of the 
Cupressaceae, and one representative of the Taxodiaceae. 
Among the angiosperms there are various genera of Le- 
guminosae, Burseraceae, Anacardiaceae, Combretaceae, 
Styracaceae, Hamamelidaceae, Guttiferae, Rutaceae 
and Zygophyllaceae. 
The next relevant question concerns which of these 
resin producers occupy habitats where resin could easily 
become incorporated into the geologic record. Intorma- 
tion regarding the environmental relations of these trees 
| 266 | 
