500 THE AMERICAN NATURALIST. [Vor. XXXIV. 
accumulation has become coal. An interpretation that the 
contained tree-trunks represented the vegetable life of that 
region would be, in the highest degree, erroneous. The lowly 
terrestrial plants of the vicinity may have entirely disappeared, 
or their remains, commingled with those of a forest vegetation, 
may attract little or no attention. Granted, however, that the 
alluvial barriers may be discovered, that the true character of 
the deposit may be determined, still there is an unusual event 
to be translated, namely, the enormous distance the vegeta- 
ble matter has been transported. To recognize this may be 
extremely difficult, if not impossible. During the lapse of time, 
elevation and folding may have taken place; denudation and 
erosion may have completely altered the topography of so vast 
an area of country ; parts of the great river basin may have 
become so widely separated that their continuity would scarcely 
be suspected. This is not an exaggerated statement ; on the 
contrary, it lies strictly within the limits of possibility. If so, 
then is the danger of misinterpretation clearly shown. 
The flooding of streams, it is said, is often quite destructive 
of fish life ; the copious sediment contained in the water being 
an undoubted cause of suffocation. During the recent flood in 
Texas I saw fish so overcome that they were easily taken by 
hand. When the waters receded their dead bodies were re- 
ported as occurring along the river banks and on the bars. 
Under such conditions it does not seem improbable that parts 
of the skeleton, and especially the scales, such as those of the 
ganoid type, should be borne seaward, and finally deposited in 
salt water, commingled with marine forms. Had a similar 
circumstance occurred in other than recent time, and had the 
remains of marine and fresh-water forms been preserved in 
the same stratum, then a fine discrimination between animals 
greatly alike in appearance, and, possibly, not presenting char- 
acters admitting of direct relations with the present, becomes 
necessary on the part of the observer would he make a correct 
interpretation. And, moreover, this hypothetical statement 
will serve to emphasize the fact that a knowledge of biology is 
of prime importance to him who would undertake the inter- 
pretation of such a record. 
