68o THE POPULAR SCIENCE MONTHLY. 



from the west coast, passes through cultivated and half -tilled lands into 

 a romantic river-valley, and then through the primitive wilderness over 

 hills and mountain-torrents, into an upland valley about three thou- 

 sand feet above the sea, in the bottom of which lies the boiling lake, 

 surrounded by a grim waste of volcanic rocks. 



The starting-place for our excursion is the little town of Roseau, 

 the chief place of the island, and the only one where the traveler will 

 find a boarding-house, situated on the west coast, picturesquely set 

 down at the mouth of a romantic valley, among sugar-cane fields and 

 palm-gardens, and framed by forest-covered mountains. Before start- 

 ing on our excursion we will make a short study of the shore, a flat 

 beach of sand and gravel, sunny, hot, and dry, but which supports a 

 characteristic vegetation. We are struck, in looking at this beach- 

 flora, with the predominance of the creeping plants, by which the most 

 diversified botanical families are represented. Their habit of growth, 

 with the multitude of rooting points it permits, gives them great ad- 

 vantages in keeping their hold on the shifting sands, and access to 

 numerous points at which they may tap the soil for its scanty supplies 

 of moisture. The succulent nature of the organs is another peculiarity 

 of these plants that will strike the Northern observer. Most of them, 

 whether they be creepers or upright, are either provided with fleshy 

 leaves, or consist of amorj)hous thick stems without expanded foliage. 

 This property, which must be regarded as a provision to diminish trans- 

 piration, is, as every one knows, not uncommon in the vegetation of 

 dry places. In the tropics it marks not only the shore plants and the 

 vegetation of the arid plains, but also the epiphytes, which live upon 

 the dry bark of the trees. European species are represented in this 

 growth by the portulaccas. Among the plants is one, Bryophylliim 

 calyci7ium, which has long been known to gardeners and botanists by 

 the faculty which its leaves possess, when broken off and laid upon 

 the ground, of developing buds on their edges, which finally become 

 independent plants. This, instead of being a merely adventitious 

 peculiarity, marked only under special circumstances, as has been sup- 

 posed, is really the normal provision of Nature for the propagation of 

 the plant. This species forms in the course of its growth two kinds 

 of leaves ; the entire leaves of the young plant, which are shaped like 

 those of the common live-forever, and, at a later stage of growth, cleft 

 leaves. The two kinds of leaves are not equally competent to form 

 buds, but the property is a peculiarity of the cleft ones. When we 

 gently draw the hand over a well-grown plant of Sryophyllum, we will 

 find the feathered leaves falling like ripe fruits to the ground, while 

 the entire leaves remain fixed upon the plant and will not be disturbed 

 by any shaking. Examining the fallen offsets a few days afterward, 

 we will find their upper surfaces crowned with a circle of sprouts 

 around the edges, while to the lower side is attached a tuft of young 

 rootlets. The plantlets live at first on the nourishing matter of the 



