326 BOTANICAL GAZETTE [ NOVEMBER 
Before discussing certain species in detail it may be well to 
outline briefly the characters upon which we must depend for 
any thorough understanding of this genus. At the outset I wish 
to emphasize the importance of unremitting field work, and the 
absolute uselessness of herbarium material unless one is fortified 
by previous familiarity with the growing plant. It should not 
be forgotten that the value of a herbarium for purposes of syste- 
matic research lies in the advantage thereby gained of having 
material convenient for morphological and histological study, and 
not in that it provides in any sense a proper substitute for the - 
living individuals. Habit as well as habitat, the texture of the | 
herbage, color of the flowers, position of the cleistogenes, ner- fis 
vation, shape and degrees of pubescence of the leaves, nature of 
the surrounding vegetation; all these will be taken into consid- 
eration by the careful ionologist, and they are each best derived 
from outdoor investigation. Moreover we should not be content 
with superficial glances at occasional plants. A large number of 
individuals should be observed, and every feature of their 
environment noted; then it will be impossible for any discrimi- 
nating botanist to makea comment such as I recently heard, that 
Viola ovata is “nothing but a hairy sagittata with ovate leaves, 
growing in dry ground.” 
In recognizing the variability of leaf-outline often presented 
by a single individual, there is a tendency to misapprehend or to 
overlook the fact that in all of the heterophyllous violets the a 
earliest leaves are practically uniform and similar in all.the 7 ao 
Species, and as they are immediately succeeded by others of a ae 
totally different type, should never be taken into account 11 ~ 
critical diagnoses. Thus the first leaf of V7. sagitfata is cordate-_ 
reniform, obtuse and crenate, exactly like the corresponding ne 
organ of V. palmata; yet in the one case the characteristi¢ = 
foliage has lanceolate, sagittate and glabrous blades, and in the — 
other broadly cordate, pubescent and more or less lobed blades. 
T am not aware that anyone has ever proposed to unite these twe 
Species on account of the similarity of their primitive leaves, 
and yet my attention has frequently been called to these exam- 
ple of early vernal foliage as an illustration of so-called “inter 
