24 
NORMAN TAYLOR 
not as such, but as it is reflected in the vegetation which we all know 
it to have controlled. Such a method is not at all in line with older 
studies, it is really an ex post facto method of determining climate 
by the character of the vegetative response. From the standpoint 
of the ecologist and plant geographer, what could be more logical 
and reasonable? Temperature factors are not what one makes them 
out to be with an elaborate instrumental or nlathematical method; 
they are rather what one finds them as reflected in the vegetation 
itself. Of course, in order to get the quality and kind of this implied 
vegetative response, we must study plants in a slightly new light, 
and Raunkiaer has devised, after Warming and a few earlier writers, 
a scheme for such a study. 
His theory is that plants react to climate by the kind and amount 
of protection exhibited by the perennating growth points during the 
winter or critical season. Upon this assumption he divides all vegeta- 
tion into several different groups of growth-forms sometimes called 
life-forms, depending on the kind and amount of protection to their 
growing buds exhibited by each. In the following account, I have 
included only those of his growth-forms that are found in eastern 
North America, which may be characterized as follows: 
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 Megaphanerophytes, trees over 30 m.; Mesaphan- 
erophytes, trees 8-30 m. ; Microphanerophytes, shrubs or trees 2-8 m, ; 
Nanophanerophytes. shrubs under 2 m. Examples of all these are 
too common to need citing. 
Chamaephytes. 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. Among local species Arctostaphylos Uva-Ursi, 
Epigaea, Convolvulus, etc., are good examples. It includes, also, 
cushion-plants. 
Hemicryptophytes. With dormant buds in the upper crust of 
the soil, the top of the plant dying down in the winter. Common 
examples suggest themselves, as all our shallow-rooted herbaceous 
perennials belong here. 
Geophytes. Perennial by bulbs, rhizomes, tubers or by root- 
buds. Examples among our native plants: most Orchidaceae, Lili- 
aceae, Sanguinaria, Hydrastis, etc. 
