1.3 



cells, which constitute embryonic tissues. These cell-groups can 

 be seen, as small dark dots, with the unaided eye, and are ren- 

 dered quite distinct by the use of a simple lens. So long as the 

 leaf remains upon the stem, there is usually no further develop- 

 ment of these cell-groups. If, however, the leaf be plucked off, 

 or drops of its own accord to the ground, an active process of 

 cell-growth and multiplication takes place in these embryonic 

 tissues, resulting in the formation of little plants, with stems, 

 leaves and roots (Figs. 2, 3). 



The mature leaves of the air-plant are so thick and fleshy, and 

 contain such an abundance of reserve material and water that 

 it is not necessary for the leaf to obtain any nutriment from out- 

 side sources, in the formation of these new plants. For this 

 reason a leaf may be pinned up on the wall (Fig. 2), and this 

 remarkable reproduction will take place, the parent leaf sustain- 

 ing the little one for some time until they die. Under natural 

 conditions the leaves drop down onto the ground and the young 

 plants quickly strike root (Fig. 3). 



^Sf. -. 



FIG. 3. 



Leaf 'of Bryophyllum. 

 Showing the development of little plants from the leaf 

 under natural conditions, the leaf having dropped into 

 the soil. (From Bailev — Cycl. Amer. Hort.). 



This remarkable ability of the leaves to produce new plants 

 without being planted in the soil, (as is necessary in the case of 

 begonia leaves, which will also produce new plants, though m a 

 somewhat different manner), has given to the plant the name 

 of "air-plant." Its botanic name is Bryophyllum, which is de- 

 rived from two Greek words meaning "sprouting leaf." The 

 species occurring in the Hawaiian Islands is Bryophyllum caly- 

 cinum, originally a native of Africa, but now distributed through- 

 out the tropical world. This species is also known, in botanical 

 books, as Kalanchoe pinnata, and Cotyledon rhizophylla. There 

 are three other kinds of Bryophyllum, one occurring only in the 

 Cape region of Africa, and two confined to Madagascar. Ijie 

 great German poet-philosopher-naturalist Goethe was much in- 



