SCIENCE-GOSSIP. 



365 



stems of Opuntia, Senecio, Epiphyllum, etc., readily 

 separate into segments, each of which will de- 

 velop into a new plant. In many columnar species of 

 Cactus and Euphorbia, while there is no special pro- 

 visions for propagation by segmentation, yet, if any 

 portion of the stem be accidentally broken off, this 

 will develop into a new individual. The leaves of 

 all the species of Cotyledon, and of Bryophyllum 

 calycinum, and many other Crassulaceae readily fall 

 away if shaken, and from the base of every one of 

 these detached leaves, or from the entire margin 

 in the [case of Bryophyllum, several buds quickly 

 develop and soon form independent plants. The 

 same obtains in Gasteria and Haworthia. Oxalis 

 forms numerous underground tubers, after the 

 manner of a miniature potato-plant. On the 

 flower-spike of Agave, or century-plant (so called 

 from the erroneous idea that it only bloomed once 

 in a hundred years), bulbils are frequently deve- 

 loped which would thus ensure the perpetuation 

 of the species, even if the seeds failed. Many 

 species of Agave only flower once, and then die 

 (monocarpie), whereas others flower periodically 

 (polycarpie). A very interesting case was ob- 

 served in a plant of Agave kewensis, a very fine 

 species, and the only one known in cultiva- 

 tion. A few years ago this plant flowered and all 

 attempts to fertilise the flowers failed, and the 

 plant, which belongs to the monocarpie series, 

 began to die. One day, to the great joy of all 

 concerned, bulbils were discovered replacing the 

 flowers at the apex of the spike. These were re- 

 moved, and a fine stock of young plants raised 

 from them. 



Not only are the various regetative parts adapted 

 for the perpetuation of the species, but the seeds 

 also are specially adapted. In Cactaceae, for 

 example, the seeds are shot-like, and embedded in 

 a pulpy fruit. In many genera, especially Opuntia, 

 these fruits are eaten by animals, including man. 

 They have much the taste of a gooseberry. The 

 seeds are not digested, but pass out in the ex- 

 creta. So great a pest have opuntias become in 

 South Africa that a law has been passed for- 

 bidding the natives eating the prickly pears as 

 the fruit is called. In Melocactus and Mamillaria, 

 the ovary is protected by tufts of dense hair and 

 spines until the seeds are matured, when it is 

 forced out on to the surface. Its brilliant colour 

 attracts birds, and thus the seeds are disseminated. 

 In the epiphytic genus Rhipsalis, the fruit is red 

 or white, and looks very like the fruit of Loran- 

 thus. Rhipsalis cassytha, the mistletoe-cactus, 

 resembles our mistletoe very closely, even to the 

 white berries. Here, too, the pulp of the berries 

 is adhesive and encloses a few large seeds, which 

 birds separate by rubbing against the bark of the 

 trees, where the seeds lodge in the crevices and 

 germinate. Another interesting fact about this 

 mistletoe-cactus is that it is the only cactaceous 



plant truly indigenous in the Old World, occur- 

 ring on the West Coast of Africa and in Mada- 

 gascar. The seeds of all xerophytes agree in 

 their rapidity of germination and development in 

 the initial stages. I may generalize, and say that 

 if seeds of xerophytes fail to germinate in about 

 three weeks, they have lost their vitality. I have 

 sown seeds of what used to be called the rose of 

 Jericho (Anastatica hitrochuntica), and within 

 twenty-four hours they have germinated with 

 their epigean cotyledons fully expanded. This 

 plant will stand being blown about the Arabian 

 deserts for months, rolling itself up into a ball. 

 When rain falls, it unfolds itself, its capsules de- 

 hisce, and the seeds germinate immediately. 

 Many similar instances could be given, but it is 

 beyond the province of this article. 



At first sight this rapid germination may seem 

 inexplicable when contrasted with the slow 

 development of the adult. A moment's considera- 

 tion, however, will show the completeness of the 

 adaptation. In the arid habitat of these plants, 

 it is obviously their duty to make the best use of 

 rain when it does fall — hence the advantage of 

 the seeds' germinating quickly, and the young 

 plants getting a firm hold before the rainy season 

 has passed. 



Thus far I have attempted, in a somewhat 

 desultory manner, to point out a few facts con- 

 cerning the denizens of the Succulent House at 

 Kew Gardens, interesting, I hope, to all lovers of 

 plants, especially those readers with a botanical 

 turn of mind. I will now append a few remarks 

 of a more special character, relating to the com- 

 mercial side of plant life. I will endeavour to 

 show that from a purely utilitarian standpoint 

 this house is of special interest. It contains a 

 rare collection of plants which yield valuable 

 commercial fibres, to say nothing of other plants 

 which, if tried, might add considerably to the 

 number of standard fibre-producing species. The 

 fibre-yielding plants contained in this house are 

 all monocotyledons. The fibres are extracted 

 from the leaves and may be termed leaf fibres, to 

 distinguish them from the bast fibres, such as 

 flax, hemp, jute, etc., or seed-hairs, such as cotton. 

 For description of the fibres, modes of cleaning, 

 uses, and market-price, reference must be made to 

 the literature on this subject. All I can do in 

 the limited space at command is to enumerate the 

 principal plants which yield fibres, attaching to 

 each their commercial names, hoping in this way 

 to draw attention to their presence in this house. 

 The more important of these are : Sisal hemp 

 ( Agave rigida var. sisalana) ; Bombay or Manila 

 aloe fibre (A. vwipara) ; Istle, or Mexican fibre 

 A. heteracantha) ; Jamaica Keratto (A. morrisii) ; 

 Mauritius hemp (Farcraea gigantea) ; silk-grass 

 fibre (F. cubensis, and F. selloa) ; Caraguata fibre 

 (Bromelia argentina) ; Ife hemp (Sansevieria cylin- 



