644 THE POPULAR SCIENCE MONTHLY. 



by a young slave, Edmond Albius, in the service of M. Ferreol Beau- 

 mont-Bellier. Albius bad noticed bow his master, who had consider- 

 able acquaintance with natural history, used to produce hybrids by 

 cross-fertilization of the various flowers in his garden. Having made 

 like experiments himself, the young slave observed that, on touching 

 with a spine of palm the flowers of the vanilla, two little yellow bodies 

 contained within changed position, and that fructification resulted from 

 the contact. A new branch of commerce was henceforth created, and 

 vanilla-beans, previously very dear, were quickly much lowered in price. 



The vanilla is a climbing plant with pulpy stem, but it can reach the 

 tops of high trees. In our greenhouses it attains proportions sufficiently 

 great to enable us to judge of its appearance. Its stem, which can be 

 easily made to ramify, is from two to three centimetres in diameter. 

 Its leaves are arranged in two rows, or are alternately distichous, as 

 the botanists say. In size they vary from fifteen to twenty centime- 

 tres, and they are slightly twisted on their short petiole, so as to appear 

 to be inserted obliquely. This torsion seems to be produced by the 

 need for the leaf of having its upper face always turned toward the 

 light. 



Besides the roots at the base of the plant and fixed in the soil, a 

 multitude of adventitious aerial roots start from the stem or the 

 branches, after the plant has reached a certain size. These roots hang 

 free so long as the stem rises vertically, but become fixed in the soil 

 when the stem touches the ground. They start from the level of a leaf 

 alongside of a tendril, with the aid of which the plant climbs trees. 



The stem, which in the interval between two leaves takes a direc- 

 tion the reverse of that taken in the next interval a zigzag is charged 

 with a thick* vesicating juice, which on being apjflied to the skin pro- 

 duces a blister. 



The flowers appear in clusters at the axils of the leaves, and are 

 numerous ; but care is taken to leave only a small number of them on 

 the plant when it is desired to have fine fruit. These flowers last for 

 only one day, and fructification, in order to be successful, should take 

 place in the morning. The instrument used for this operation is a 

 pointed piece of bamboo. A skilled man can fecundate as many as 

 one thousand flowers in a morning. One month after fecundation the 

 fruit has attained its full size, yet it has still to remain on the plant 

 six or seven months more before it reaches perfect maturity. 



The flowers of the vanilla have none of that richness of color so 

 common among orchids. They are whitish or yellowish, according to 

 the species to which they belong. Apart from those which are culti- 

 vated on account of the perfume of their fruit, the others possess only 

 a purely botanical interest. 



A physiological detail that is worthy of mention is the attraction 

 of the stigmas of these flowers for the pollen offered to them. Neu- 

 mann the younger had frequent occasion to notice this while experi- 





