366 APPENDIX 
into two sections, characterized by the superior or inferior 
ovary (218, 225). Further examination will show that the 
morning-glory belongs to the former class, which is in turn 
divided into two sections, according as the corolla is regular, 
or more or less irregular. We see at once that we must look 
for our specimen in the group having regular corollas. This 
we find again subdivided into four sections, according to the 
number and position of the stamens, and we find that the 
morning-glory falls under the last of these, — ‘‘ Stamens as 
many as the lobes or parts of the corolla and alternate 
with them.” A very little further search brings us to the 
family Convolvulacee, and turning to that title in the de- 
scriptive analysis, we find .under the genus, Ipomea, a full 
description of the common morning-glory, in the species 
Ipomea purpurea, and of the sweet potato in the species 
Ipomea batatas. 
Making collections. —Mere labeled aggregations of species 
are not recommended, but the collection of examples illus- 
trating special points in morphology and plant variation 
may be made with profit; such, for instance, as the adapta- 
tions observed in tendrils and stipular appendages, the 
various modifications of leaves and stems to serve other 
than their normal purposes, or the different forms of leaves 
and flowers on the same stem, or on different plants of the 
same species. A collection made with some specific object 
in view would also be instructive, and might prove of great 
value; for instance, to get together examples of all the 
troublesome weeds of a locality for the purpose of studying 
their habits and devising means for their eradication ; or of 
all the native useful plants, with detailed analyses of their 
economic properties, and observations on their habits and the 
practicability of further developing them. In short, wherever 
collecting is carried on, it should be done with some object 
other than the mere identification of species, which often 
results in greater detriment to the wild plants of a neighbor- 
hood than profit to the collector. 
