350 ANNUAL OF SCIENTIFIC DISCOVERT. 



known to Ray, who states that such plants may live even five years. The 

 second physiological group, to which I shall now direct your attention, has 

 this property in common with the preceding, that the stem, after flowering 

 and ripening the seed, perishes, together with the root by which it is nour- 

 ished. In this respect it may be termed an annual ; and as examples, may 

 be quoted the tulip, onion, monkshood, and very many of the plants termed 

 herbaceous. These differ, however, from the ordinary annuals, or once-flow- 

 ering plants, by the production, at the base of the stem of the present year, 

 of a bulb or tuber, destined in the following spring to form its own roots, 

 independent of the parent bulb or tuber, now exhausted and dead. This 

 mode of secondary reproduction or extension is well illustrated by the com- 

 mon orchids, as the common Orchis mascula, where the bulb which is to give 

 rise to the stem and flowers of next season may be observed of a paler color 

 and firmer texture than the one in the course of being exhausted and ready 

 to die. In the case of the two bulbs of the Neottia spiralls, or ladies' traces, 

 Keith, in his " System of Physiological Botany," i. 38, states : " If a pair of 

 these knobs is taken and separated, and then immersed in water, the one 

 will be found to sink, and the other to swim. This is a phenomenon which 

 seems also to have puzzled the simplists of antiquity not a little, and to have 

 given rise to a great deal of idle and superstitious conjecture. It was thought 

 that the knob that swims must necessarily have possessed some peculiar and 

 potent properties, and accordingly some potent properties \vere liberally 

 ascribed to it. If prepared in a particular manner, and worn about any one's 

 person, it was believed to have the singular property of exciting, by means 

 of proper management, a violent attachment to the wearer in the breast of 

 any one lie pleased. And this belief," he adds, " is still a vulgar error 

 among the ignorant and superstitious." The group to which we have now 

 referred, has been, in a great measui-e, overlooked by more recent botanists, 

 although its characteristics were known to Ray, and confounded by them 

 with the group we now proceed to consider. This third group was denomi- 

 nated by Linnixms Suffrutices, and thus defined, " truncis sublignosis quo- 

 tannis fere supra raclicem pereuntibus." (Phil. Bot. 74.) Lindley has a di- 

 vision of plants which he terms Polycarpous, " having the power of bearing 

 fruit many times without perishing," and a subdivision of this group he 

 terms Rhizocarpous, " or those whose roots endure many years, but whose 

 stems perish annually, as herbaceous plants," (Introd. to Bot., 475.) The 

 modifications of this group exhibit considerable variety of character. The 

 following may readily be distinguished: 1. Where the flowering-stem and 

 leaves perish, while the collar and root remain, for the benefit of the buds to 

 be evolved from the former in the following spring, such as strawberry and 

 horseradish. 2. Where the flowering-stem perishes together with the collar, 

 but Avherc rhizomes are produced with buds of an equally monocarpous 

 character as the parent, as mint. 3. Where the stem, collar, and root, per- 

 ish after reproduction, having given rise to a stem with its roots capable of 

 outliving the winter, and producing flowers and fruit during the following 

 season. The common rasp is a good example of this group. 4. Where the 

 whole plant dies after maturing the seed, and forming from the stem a tuber, 

 as in the potato. Here we have an aggregation of flower-buds destined to 

 produce individuals with the annual or monocarpous character. These 

 groups of rhizocarpous plants do not seem to have occupied, to any extent, 

 the consideration of botanists, although, in a physiological point of view, of 

 great interest. The field, indeed, may be regarded as in a considerable 



