LINTTEAN SOCIETY OF LONDON. 35 



of whicli all the walla iu Malta are composed, and appears at the 

 surface like a green fringe around each stone. It covers the tops 

 of the -R-alls in many places, as well as the lofty fortifications. 

 It not only forms luxuriant borders to the fields, but invades 

 the cultivated soil ; so that when, as is too often the case, the 

 weeds are not uprooted, a field will look as yellow as an English 

 meadow with buttercups. It is propagated entirely by bulbs. 

 If a large plant be dug up in January, growing, we will say, 

 amongst loose stony debris, it will be found to possess a long 

 tapering s^ewj *, throwing off thread-like lateral roots, and bearing 

 minute leaf-scales with small wliite bulbils at intervals, as well as 

 several larger ones at the crown below the cluster of leaves. The 

 fine thread-like rhizome extends downwards, sometimes to a 

 depth of more than a foot, and proceeds from a bulb of the 

 previous season, from which this vertical subterranean stem has 

 grown upwards. This bulb has outer, brown scales. Sometimes 

 there are two bulbs, connected by the stem, included within the 

 scales. The bulb itself consists of very thick scales, one over- 

 lapping the other, a cross-section of a scale having a crescent 

 shape. In many instances, when the plant grows as above, the 

 stem proceeds further downwards like a thread ; but after a 

 certain distance it suddenly increases in diameter, forming a 

 short rod-like structure about 1| to 2 inches long, with a bulb at 

 the end. This explains how it is enabled to reach great depths, 

 from which new plants arise in a subsequent season. On the 

 other hand, the great length of the subterranean stem explains 

 how the plant is enabled, so to say, to " climb up " between the 

 stones of the walls, thus accounting for the green fringe which is 

 often seen all round the stones in the lower part of the walls in 

 Malta. 



Besides the bulbs thus formed in a vertical line, at all depths, 

 the oxalis often produces runners above-ground. They only 

 occur, however, on luxuriant plants, such as those growing by 

 the watercourse in the A\'^ied Encita, or in the rubbly ground 

 within the ditches of the fortifications, &c., or, again, iu the rich 

 soil of the orange-gardens at Cairo. The runners, however, do 

 not root like those of strawberries, but produce bulbs at the 

 nodes, so that a number of young plants can be produced at a 

 short distance from the site of the pai'ent plant. 



It afl'ords certainly one of the most extraordinary instances of 

 a very extensive muUiplication, and that solely by the vegetative 

 system, indicating the tact that the assumption that intercrossing 

 of flowers by fertilization is necessary to ensure vigour is totally 

 unfounded f. It might be thought that, as it is only the short- 

 styled form which exists, the pollen might readily fall upon and 

 pollinate the stigmas, thus assuring at least self-fertilization. It 

 undoubtedly does fall down upon them, as there are ten anthers 



* Not roof, as described by Mr. Ball, l. c. 



t Just as is the case with Elodea canadensis iu this country. 



d2 



