T I S 



502 



TIS 



Dune specie* of plant*. The principal rarictie* of Paren- 

 chyma distinguished by Meyen are 



Fig. I. 



a 4 



V* 1 



1. The cubical, which exists in the cuticle of some 

 leave*, and is not unfrcquently met with in bark and pith, 

 as in the pith of Viscum album, (c, Fig. 1.) 



The rnlamnar, of which there arc' two varieties: the 



rifHnrlrir<tl 'cylindrenrhymu of Morrcn , examples of 



which may be seen in Cham nnd in Agaricus inuscarius ; 



. ,-i,tii,iiii\i .hymn;, frequently seen in the 



lie hark of plants, and when compressed it be- 



inuriform tissue (t, Fig. 1;, which is constantly 



: in the medullary rays, and has its name from the 



beitv.; arranged as bricks in a wall. 



:t. The ii <! : the natural form of parenchyma 



when the cells are of equal size and exert on each other 

 equal pressure, and when cut present a hexagonal form. 



1 



1. The strllatrd (actinenchyma), in which the cells, 

 from the irregularity of their walls, assume a star-like form, 

 seen in Musa. 



The tubulated, seen in the epiphlaeum of many 



plants: other forms, as conical (conencnyma ; ft, Fix. 1 . 



oval {iimichyimi , fusiform (atractgnchymd), sinuous 



branched :i;jled (d<e- 



;ive been described b\ Morren. 



differs from Parenchyma in the cells 

 always having an elliptical form which taper to theii 

 extremities, where they overlie each other. This form of 

 tissue is found only in 'the bark and wood, and is a tran- 

 sition from cellular to what is called woody tissue. Meyen 

 applies this term esp< . ially to the tissue finning the wood 



In these families thi- 

 is marked with do'ts, which are surrounded by a circle. 



Fig. '2. 



(Fir. Z) These dots were formerly supposed 1 

 ana to seci. -inoiis matter which abound-, in them, 



and hence it was called glandular woody ti--ue.' Tin 

 nx-arche.- have hov. u (hit 



dobt are the result of the development of fibre wilhii 

 alls of the cells, and in this Mrw the Prosenchyma 

 not only constitutes a transition from cellular to \: 

 tissue, but also a transition from libro-cellular to fibro- 

 vascular tissue. 



- 'if Cells. The vesicle of cellular tissue 

 it rises from its cytoblast is a thin transparent m.'i 

 which as it eniarsres becomes thirki-ncd from within b\ 

 the i, rr nutriment which is contains 



in the cell. This cell in the early ktagcs of its growth is 

 filled with a fluid, at firt clear, but afterward* opa' 

 f. "in tin- development in it of minute granules, 

 granule* are of various shapes and sizes, and always exces- 

 sively minute. In their early stages they possess the 



characters of starch, more particularly the proper' 

 assuming a blue colour when 

 tincture of iodine. In the older . 



>e character of starch, nnd possess nv 

 Some of them, and these more minute than thos* 

 arc not coloured by iodine, and arc soluble in alcoho! 

 partake of a resinous character. They jr iliar 



colour to the elaborated sap, v and 



in plants with milky juices constitute the ca 

 which they yield. They seem also to be ' 

 of the volir sins, balsams, rums, &c. t 



yield. [SECRETK nothcr set of glubiiUi 



are also found present in old cells, and these conv 

 what is called chlnrophyl, or chromulf, and exist espc 

 in the cells of plants < 



[Su'.l It is from t': 



vh that the cc! 



appropriated by the walls of the cell they are 

 into a substance 



It is from tl vini: in :i 



plants, that the cells arc 



uembrane in many eases bccon. hard, 



as in the stones of manyfru I oflhe ]' 



Maerocarpa, and the wood of r.: In simpl* 



lular tissue and in woody tissue this material is ap]<lied 

 equally to the whole e pillar 



: in the tibro-cellular and fibro-vascular tissues it is 

 appropriated in the form of fibre. 



Another class of bodies found in the interior of < 

 and which appear to have nothing to do with tl!' 

 of the plant, are those crystalline bo. I llaphides. 



They occur singly or in bundles, and have an aeieular 

 form, and are long or short according to ciituiu>1: 

 In length tl :-e from J^th to Tjmth part of an inch. 



These crystals were first obsened in tin 1 proper juices of 

 plants and have been subsequently found in all paru ut 

 plants where celluln: They \\ere formerly 



supposed to exist between the cells, but later ohs. 

 have seen them in cells, and they probably exist in 

 situations. The form of these bodies is not satisfactorily 

 determined. Mold describe* thorn ; four- 



sided prisms vanishing into poiir 

 the latest ol 



four-sided prisms, but not always n<,'ht 

 which are conglomerated are called crystal -glands '.'kryutal- 



i bv Mcvcn. They seldom present more than the 

 pyramid of each little crystal composing them. Tin 

 portion in which they exist in plants is sometimes very 

 ureat. In some spec:, cec, according to Qui 



the crystals equal the wcicM of th<- ilried ti 

 hundred grains of Tu .irb-root 31 



and 40 grains oi 

 Seilla maritima yielded 10 grains. In m 



Is are composed of 

 lime. Raspail says the cr. 

 four-sided prisms will 



of the phosphate, six-siiied prisms. In (.'ham crystals of 

 carbonate of lime occur in preat abundance on the out- 

 side of tht I we ha\t- ohscncd them in the in- 

 tercellular passages immediately under the epidermis, 

 but they do not occur in the interior parts of the plant. 

 Schiible'r found that the crystal-glands of Hydiuius 

 tallophorus consisti d of carbonate of lime, and Saigey and 

 De la Fosse found silica in th. l the Mi:. 

 Jalapa. Silica the 

 Graminacca-, but is .- 

 the hardness to ' 



i article of commerce und. 



't l leu ill of the c 



in plants it may be inferred that - form tin : 



side 's the above. Thene bixlies do in : 

 :irts of the tissues in which tlu\ 



.^red by Link to calculi and oil 1 .. >:is in 



the animal kingdom. This view is rendcreii 

 by the fact 



nients wliieh the plants tal, 



nutriment. Mejeii h:ui pointed out , 'ants 



.11: near the sea will thn> iMtvi; 



of clil <Iium in II. ' I_M> 



nd we have fon 



i wliich it 

 'ance. JL'hosphate of lime 



