302 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 Piniis-Junipenis 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 

 b)eing most important: 



L 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 veiw 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: 



Ruhus nigrobaccus , Smilax herbacea, 



Aralia raceniosa, Vitis vulpina, 



Parthenocissus quinque folia, Prunus virginiana, 



Nabalus albus, Rhus aromatica, 



Toxicodendron pubescens, Helianthus struntosus, 



Agastache nepetoides, Steironema ciliatum, 



4. Herbaceous Layer. Exhibiting more or less alternation 

 with 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.^" 



Wdshingtonia claytoni, Aralia nudi flora, 



Vagnera siellata, Meibomia dillenii, 



Lespedeza violacea, Galium circaezans, 



Galium triflorum, Phyrma leptostachya. 



Polygonum virginianum, Vagnera raccmosa, 



Salomonia commutata, Monarda fistiilosa. 



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 Biologiqvies pour la geographic botanique. 

 Oversigt over det Kgl. Danske Videnskabernes Selskabs Forhandlinger, 

 1905 : 347-4:^7. 



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. 



