3°2 
The Ohio Naturalist. 
[Vol. VIII, No. 6, 
This formation constitutes a forest habitat quite different in 
several respects from that of the preceding formation. The pri¬ 
mary layer being deciduous, and, as a whole, being largely com¬ 
posed of species (oaks) coming into leaf rather late in the season, 
and, even then, not casting a dense shade, the relative amount of 
insolation reaching the lower layers in the oak forest is quite 
large; much larger than in the Pinus-Juniperus forest. Due 
in a large measure, probably, to this relatively greater amount 
of insolation there are developed in the oak forest much more 
pronounced layers. The following layers are there evident, 
aside from the Primary Layer the Shrub and Herbaceous Layers 
being most important: 
1. Primary Layer.—Composed of the facies and other 
large trees. 
2. Secondary Layer.—Younger individuals of the species 
constituting the primary layer, together with a very few large 
shrubs and small trees. Not a well defined structure in the 
formation as represented on Cedar Point. 
3. Tertiary or Shrub Layer.—Composed of bushes and 
shrubs together with a tangle of lianas and certain tall herbaceous 
plants: 
S mi lax herb ace a, 
Vitis vulpina, 
Prunus virginiana, 
Rhus aromatica, 
Helianthus strumosus, 
Steironema ciliatum, 
Rubus nigrobaccus, 
Aralia racemosa, 
Parthenocissus quinquefolia, 
Nabalus albus, 
Toxicodendron pubescens, 
Agastache nepetoides, 
4. Herbaceous Layer. Exhibiting more or less alternation 
w 7 ith the Tertiary Layer and often grading imperceptibly into it, 
being at the same time of about equal importance with reference 
to the formational structure. This structure is very largely com¬ 
posed of herbaceous perennials with well developed underground 
stems, “ Geophytes, ”—Raunkiaer. 10 
Waskingtonia claytoni, Aralia nudiflora, 
Vagner a stellata, Meibomia dillenii, 
Lespedeza violacea, Galium circaezans, 
Galium triflorum, Phyrma leptostachya, 
Polygonum virginianum, Vagnera racemosa, 
Salomonia commutata, Monarda fistulosa. 
5. The Ground Layer. This indefinite and variable layer is 
characterized by a few fungi and mosses living on the humus and 
dead leaves. 
10. Raunkiaer, C. Types Biologiques pour la geographie botanique. 
Oversigt over det Kgl. Danske Videnskabernes Selskabs Forhandlinger, 
1905 : 347-437. 
Liberal translation into German by Dr. F. Fedde. In Aus de Natur. 
Oct 1 & 15; Nov. 1 & 15; Dec. 1 & 15; 1907, and Jan. 1 & 15, 1908. 
