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 Convolvulacece, 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. 



