6 THE AMERICAN NATURALIST. [VOL XXXIII. 
maximum L., Fraxinus Americana L., F. Pennsylvanica Marsh., F. 
lanceolata Borck. 
Scattering from the coniferous zone : 
Gymnospermæ : Chamecyparis thyoides (L.) B. S. P., Pinus rigida Mill. 
Angiospermæ : Diospyros Virginiana L., [lex opaca Ait. 
CONIFEROUS (SOUTHERN) ZONE. 
Gymnospermæ : Pinus rigida Mill., P. echinata Mill, P. Virginiana 
Mill., Chamacyparis thyoides (L.) B. S. P. 
Angiospermae: Quercus Phellos L., Q. nigra L., Q. minor (Marsh.) 
Virginiana L., Crategus uniflora Münch., Prunus maritima Wang., Ilex 
opaca Ait., Diospyros Virginiana L. 
Scattering from the deciduous zone : 
Gymnospermæ : Pinus Strobus L., Tsuga Canadensis (L.) Carr. 
Angiospermæ : Castanea dentata (Marsh.) Sudw., Hicoria alba (L.) 
Britton, Liriodendron tulipifera L. 
SPECIES MORE OR LESS ABUNDANT IN BOTH ZONES. 
Populus tremuloides Michx., Salix nigra Marsh., Betula nigra L., B. 
populifolia Marsh., Alnus rugosa (Ehrh.) Koch., Quercus ilicifolia Wang., 
Sassafras sassafras (L.) Karst., Liguidambar styraciflua L., Prunus 
serotina Ehrh., Acer rubrum L., Nyssa aquatica L. 
It may be noted that three species (Q. alba, Q. coccinea, and 
Q. velutina) are listed as characteristic trees in both zones. 
This means that they are so abundant in both that any descrip- 
tion of the prevailing vegetation in either would be incomplete 
unless they were mentioned. 
On the other hand, the species listed as abundant in both 
zones are equally wide in their distribution with the three 
species just mentioned, but none of them is so abundant 
as to be characteristic, being more or less scattered and usu- 
ally following minor surface features, such as water courses. 
swamps, roadsides, etc. 
If a complete enumeration of the trees which inhabit each 
zone be studied, it may be readily seen that the deciduous zone 
contains the greatest number and diversity of genera and spe- 
_ cies, and that they are, as a rule, well mixed; no one species 
forming the bulk of the forest over any considerable area. In 
| the coniferous zone, on the contiary, the monotonous uniformity 
