vall] 



{Tljf 5Trws"ur2 al 2S0tani). 



1202 



is found wild in many parts of Southern 

 Europe. It is a perennial herb, and has a 

 very short stem, bearing a tuft of thin 

 narrow green grass-like leaves, hardly a 

 quarter of an inch broad, but often a yard 

 or more long, with their apices finely saw- 

 toothed : the stem also sending off suckers 

 from its sides, which ultimately take root 

 and produce new plants. The two sexes 

 are borne on separate plants. The male 

 flowers are extremely minute, white, and 

 of a globular form, without special stalks, 

 but seated upon and entirely covering a 

 short general stalk of a conical form ; the 

 whole being enclosed while young in a 

 very short-stalked spathe, which splits into 

 two or three valves at maturity, when 

 also the little flowers become severally 

 detached from the general stalk, and rise 

 by their natural buoyancy to the surface 

 of the water, where their three-parted 

 calyx expands and permits of the escape of 

 the pollen from the anthers. The stamens 

 vary from one to three in number, and 

 alternate with several rudimentary ones. 

 The female flowers are altogether different 

 from the males. They have a cylindrical 

 ovary, bearing three small spreading calyx- 

 i lobes at the top, and contain three rudi- 

 i mentary stamens, and three large oval 

 ' often split stigmas. Each flower is en- 

 closed in a tubular spathe, borne singly at 

 | the end of a very long slender spirally- 

 twisted stalk, which uncoils more or less 

 I according to the depth of the water, so as 

 | to allow the flower to float upon the sur- 

 face, where it expands and is fertilised by 

 its stigmas coming in contact with the 



Vallisneria spirali 



pollen of one or more of the very nu- 

 merous detached male flowers floating 

 about. After this latter process has taken 

 place, the spiral stalk coils up again, and 

 by that means conveys the flower to the 

 bottom of the water, where it produces a 

 cylindrical berry varying from half an inch 



to two inches in length, and containing 

 numerous cylindrical seeds marked with 

 longitudinal ridges. 



The leaves of this plant form an ex- 

 ceedingly beautiful object under the mi- 

 croscope, the extreme tenuity and trans- 

 parency of their cellular tissue allowing 

 the observer to watch the movement of 

 the fluid contents of the cells. [A. S.] 



VALLOTA. A genus of Amaryllidacece, 

 much cultivated for the beauty of its 

 rich scarlet flowers. There is but one 



Vallota purpurea. 



species, V. purpurea, of which some varie- 

 ties occur. This is a stoutish bulb, with 

 lorate leaves, and a scape supporting se- I 

 veral large erect flowers, which have a I 

 straight tube, a funnel-shaped limb, con- J 

 niving filaments adhering by one side only 

 to the tube, and a declinate style. It is 

 closely allied to Oyrtanthus. [T. M.] 



VALONIA. A commercial name for the 

 large capsules or acorn-cups of Quercus 

 JEgilo-ps. 



VALOXIACE.E. A natural order of 

 green-spored Algce, characterised by the 

 rooting variously-shaped frond, made up 

 of large bladder-like cells filled with a 

 green watery endochrome. In Anadyo- 

 mene the cells are disposed in a fan-shaped ! 

 membrane ; in Charncedoris the stem is | 

 annulated ; in Penicilhts there is a spongy : 

 stem formed of interwoven filaments. ' 

 In both these genera it is terminat- i 

 ed by a brush-like head. Valonia forms ' 

 irregular masses of large cells or sacs i 

 repeatedly constricted, resembling the 

 membranous eggs of some mollusc. In 

 Dictyosphceria, which consists of an irre- 

 gular membrane, the surface is marked 

 with the outlines of hexagonal cells, in- 

 dicative of strong dissepiments within. 

 In Blodgettia, which has exactly the habit 

 of a large Cladophora, the walls areformed 

 of two or three membranes, the innermost 

 of which is veined and reticulated, a free 

 vein in each mesh of the network being 

 terminated by a short necklace of spores. 

 They are all natives of warm seas, not a 



