1922] HARVEY—PINE FORMATION 35 
pine canopy. It would be of interest to know whether these 
shade differences are correlated with floristic or vegetational dif- 
ferences. This problem unfortunately escaped attention in the 
fiel 
Growth forms 
Since the appearance of RAUNKIAER’s work in 1916, ecologists 
have viewed the influence of temperature factors from a radically 
new viewpoint. He points out that climatic conditions are reflected 
essentially in the biological nature of the vegetation, that is, in 
the nature and extent of the protection possessed by the perennat- 
ing growth points during the winter or critical season. Upon the 
basis of this generalization he classifies vegetation into a series of 
TABLE IV 
LIGHT DETERMINATIONS, Bic PINES FORMATION 
Station Association Ratio 
Rect ee. ory pt Lower Pines I:15 
BA as cat es cis Lower Pines i372 
Py Ng ae Upper Pines £703 
Toe Pe eer White pine canopy £57 
PO Pe ee Yellow pine canopy 1:30 
life (or growth) forms. The following characterization of life 
forms and the abbreviations used are added for convenience of 
reference.4 
Phanerophytes.—Woody plants of all types, both evergreen and 
deciduous, and exhibiting the least amount of protection from the 
cold, as showing the greatest amount of exposure. The group may 
be divided into M egaphanerophytes (MG), trees over 30m.; 
Mesophanerophytes (MS), trees 8-30 m.; Microphanerophytes (MC), 
shrubs or trees 2-8 m.; Nanophanerophytes (N), shrubs under 2 m. 
Chamaephytes (CH).—Perennial by virtue of the fact that the 
buds are just above the ground, or on the surface, and are thus 
often protected by the snow blanket. 
Hemicryptophytes (H).—With dormant buds in the upper crust 
of the soil, the top of the plant dying down in winter. 
*Tayzor, N., The growth forms of the flora of New York and vicinity. Amer. 
Jour. Bot. 2223-31. 1915. 
