MESEMBRYANTHEMUM. A most ex- 

 tensive genus of Mesembryacece, the name 

 of which, derived from the Greek words 

 mesembria, mid-day, and anthos, flower, 

 is applied to these plants because many 

 of them open their flowers only for a short 

 time in the middle of the day. Between 

 three and four hundred species are describ- 

 ed, and upwards of one hundred and fifty 



Mesembryant 



aeitoitleurn. 



are cultivated in our gardens, where some 

 of them are favourites on account of their 

 showy flowers. They are very succulent 

 and grow in hot sandy plains, the genus 

 being almost entirely confined to the Cape 

 of Good Hope. Their leaves are very vari- 

 able in form, but almost always of a thick 

 fleshy texture ; and their flowers have four 

 or five sepals united by their base and co- 

 hering with the ovary, and numerous nar- 

 row petals generally in several series. The 

 ovary is one or many-celled, and bears 

 numerous stigmas ; and the one or many- 

 celled fruit opens by means of slits dis- 

 posed in a star-like manner upon the top, 

 each cell containing numerous seeds. 



M. crystallinum, a native of the Canary 

 Islands and Greece, as well as of the Cape 

 of Good Hope, is the common Ice Plant of 

 our gardens, so called in consequence of 

 every part of the plant being covered with 

 small watery pustules, which glisten in the 

 sun like fragments of ice. Large quantities 



Mesembryanthemum tigrinum (leaf). 



of the plant are collected in the Canaries 

 j and burnt, the ashes being sent to Spain for 



the use of glassmakers. M. edule is called 

 the Hottentot's Fig, its fruit being about 

 the size of a small fig, and havinga pleasant 

 acid taste when ripe. The leaves, also, of 

 several species are eatable, those of M.pu- 

 rjioniforme being a good substitute for 

 spinach ; but some, such as M. tortuosum, 

 possess narcotic properties, and are chewed 

 by the Hottentots for the purpose of pro- 

 ducing intoxication. The fruits possess 

 hygrometric properties, the dried shrivel- 

 led capsules swelling out and opening so as 

 to allow of the escape of the seeds when 

 moistened by rain, which at the same time 

 fits the soil for their germination. [A. S.] 



MESENTERICA. The mycelium of cer- 

 tain fungals. 



MESOCARP. That part of a pericarp 

 which lies between the outer and inner 

 skins or integuments. 



MESOCHIL, MESOCHILIUM. The in- 

 termediate part of the lip of such orchids 

 as have this organ separated into three dis- 

 tinct portions. 



MESOCHL^ENA. A small genus of east- 

 ern tropical ferns, of the affinities of which 

 different opinions are held. The plants 

 have the aspect of the larger species of 

 Nephrodium, and their oblong or hippocre- 

 piform indusia have a longitudinal attach- 



: ment along the middle of the sorus, after 

 the manner of Bidymochlcnna, with which 



j the genus is therefore associated by some. 



! Others regard the attachment as merely an 

 exaggeration of the normal condition of 

 Nephrodium, and class Mesochloena as an 



j aberrant form of that genus. [T. M.] 



I MESODERM. The middle layer of 

 tissue in the shell of the spore-case of an 

 j urn-moss. 



MESOGLC3A. A genus of dark-spored 

 ! Algce, consisting of extremely gelatinous 

 : marine seaweeds, with a solid centre and 

 ! radiating slimy branched threads procluc- 

 1 ing obovate spore-cases at their base. It 

 resembles Chordaria, but is still more ge- 

 latinous. Several species are common on 

 our coasts ; most of them are found also in 

 the United States, and one species is met 

 with in the Philippine Islands. They grow 

 on other Algce, on plants like Zostera, and 

 occasionally on stones. The purple species 

 belong to the genus Nemalion amongst 

 rhodosperms. rM. J. B.] 



MESOPHLCEUM. The cellular integu- 

 ment of bark, overlying the liber, and un- 

 derlying the epiphlceum. 



MESOPHYLL. All the interior paren- 

 chyma of a leaf, lying between the two 

 skins. 



MESOPHYTUM. The line of demarca- 

 tion between the internode and petiole. 

 MESOSPERM. The same as Sarcoderm. 

 MESPILODAPHNE. A genus of Brazil- 

 ian trees of the laurel family. The leaves 

 are net-veined, the flowers disposed in 

 axi llary panicles, each wi th a funnel-shaped 



