EKDOPHLETJM. 



ENDOSMOSIS. 



IT. Flowers furnished with true calyx tad corolla, free from 



the ovary. $J 

 . Tlowen half herbaceous, 2-3 pcUloideoum. Albumen 



Copious. 



fkilfdnfttr. Sepals 0. Petal* 2. Stamen* 3, of which 2 are 

 abortive. Embryo axile, in fleshy albumen. 



Jfyiidacmf Ekipali 3. Petals 8. Stamens 3, fertile. Carpels 

 opposite sepal*. Placenta parietal. Embryo minute, on the outside 

 of fleihv ^'"HHT ' 



Cb*MMtfiia<>.-8epal. 8. Petals 3. Stamen. 6 (or 3). Carpels 

 opposite sepals. Plaoento axile. Embryo troohlear, half immersed 

 ' S -. . mm 



Afoyafmr. Sepals 3. Petals 3. Stamens 3 (anthers 1 -celled). Car- 

 pel* opposite petals. Placenta) parietal Embryo minute on the 

 outside of fleshy albumen. 



JrxcALxa. Flowers herbaceous, dry and permanent, sc&rious if 

 coloured. Albumen copious. (Some CalUs have no albumen.) 



Jvtcaettr. Flowers scattered. Embryo minute, undivided. 



Oronliatta. Flowers spadiceous. Embryo axile, with a conspicuous 

 cleft on one side. 



LILIALE&. Flowers hexapetaloideous, succulent, and withering. 

 Albumen copious. 



GMitntuxa. Perianth surrounded by a calycine involucre, the 

 inner bracts of which are coloured and petaloid. 



MtlanUtaeta. Perianth naked, fiat when withering. Anthers turned 

 outwards ; styles distinct Albumen fleshy. 



Liliaeta. Perianth naked, flat when withering. Anthers turned 

 inwards ; styles consolidated. Albumen fleshy. 



PoHltdtracta. Perianth naked, circinate when withering. Anthers 

 turned inwards. Albumen mealy. 



AUSMALES. Flowers 3-6, petaloideous, apocarpaL Albumen none. 

 (Some Alintaeta are absolutely 2 <J .) 



Butomacta, Flowers S, petaloideous. Placenta: many -seeded, 

 netted, and parietal 



Alitmaettr. Flowers 3, petaloideous. Placenta: few-seeded, simple, 

 anil axile, or basal. Embryo solid. 



Jtmcaguuueir. Flowers scaly. Placenta) few-seeded, simple, and 

 axile, or basal, slit on one side, with a very large plumule. 



The Endogenous Orders probably contain more plants yielding food 

 for man, and less plants yielding poisons in proportion to their num- 

 bers, than those belonging to Exogens. The Graminaceir are found 

 all over the world, and are cultivated by most civilised and semi- 

 civilised nations, and yield a large proportion of the substantive food 

 of the human family. Palms are of the utmost importance in coun- 

 tries where they grow, yielding fruits, wine, sugar, sago, and other 

 product*. Many of them yield starch from their root-stocks, as the 

 arrow-root plant*, Arums, Orchises, and the like. Aromatic secretions 

 are yielded by the Gingers, and deleterious substances by the if dan- 

 Utaceir and Araeea more particularly. 



ENDOPHLEUM. [BABK.] 



I:M>OI:HI/..K 



KNIMXSMOSIS, a name given by Dutrochet to the process by which 

 fluids pas* from the exterior to the interior of a cell This process 

 seems to result from two distinct agencies, which are always brought 

 into operation where fluids pass through a membrane. The one is 

 the imbibition of the fluid by the porous cell-membrane, and the other 

 is the mutual diffusion of miscible fluids. From the researches of 

 Matteucci and others there can be little doubt that the passage of a 

 gas or liquid through an animal or vegetable membrane is but the 

 modification of the process of attraction by which fluids are absorbed 

 by solid bodies. This process is carried on with various degrees of 

 force in different materials, and seams to depend on the degree of 

 attraction subsisting between the particles of the solid and those of 

 the fluid. Matteucci found that when glass tubes of about three- 

 quarters of an inch diameter were filled with fine sand previously 

 dried, and introduced without pressure, and were immersed at their 

 lower ends into the following liquids, the action of imbibition raised 

 the liquids in the tubes to the following height : 



Solution of Carbonate of Potash . . .85 millimetre*. 

 Solution of Sulphate of Copper ... 75 

 Serum of Blood ...... 70 



Solution of Carbonate of Ammonia 62 



Distilled Water ...... 60 



Solution of Common Salt .... 68 



Milk ........ 5* 



White of Egg, diluted with its own volume of 1 ... 

 water . ...... ; 8 ' 



In these can* the imbibition took place at first rapidly, then more 

 slowly, and ceased entirely at the end of ten hours. When thick 

 solutions of gum, or starch, or fixed oils were employed, scarcely any 

 imbibition took place, and it was but little more when strong saline 

 solutions were used. The degree in which different fluids paas into 

 different solids will be seen in the following table : 



Sand. Pounded r.lsw. "aw-dnst 



Alcohol . . . 85 mill. . 175 mill . 136 mill. 

 Water . . . 175 . 182 . 60 



Thus showing that water passed more freely than alcohol into sand, 

 but leis freely into saw-dust, and both fluids passed with equal facility 

 into pounded glass. The size of the tubes employed in these experi- 

 ments and the temperature affected considerably the results. The 

 fluids rose higher in proportion as the temperature increased. This 

 enable* us to understand the influence of heat on life by the physical 

 effects it produce*. 



Not only is the passage of fluids from the exterior to the interior 

 of a cell facilitated by the attraction between the cell-wall and the 

 fluids, but the fluids on either side of the membrane have a tendency 

 to mix with each other, which cannot but assist in this process. 

 Professor Graham has shown that not only have gases an inherent 

 tendency to mix with each other, independent of the laws of gravity, 

 but that this law also applies to the miscibility of liquids. In a 

 Memoir on this subject in the ' Philosophical Transactions' for 1850, 

 be has shown the laws which this diffusion of liquids obeys. Different 

 substance* possess this property in different degree*. Thus, when 

 solutions of the following substances were used, of the strength of 

 20 parts to 100 parts of water, the relative quantities diffused in a 

 given time were as follows : 



Chloride of Sodium . 

 Sulphate of Magnesia 

 Nitrate of Soda . 

 Sulphate of Water . 

 Crystallised Cane-Sugar 

 Starch-Sugar (Glucose) 

 Gum Arabic 



58-M 



27-42 

 51-56 

 89-89 



26-74 

 26-94 

 13-24 



The experiment* from which these results were obtained, were 

 performed by inverting a phial containing the solution to be diffused 

 in a large jar of pure water. The diffusion was stopped after seven 

 or eight days, and the amount of diffusion was determined by evapo- 

 rating the water of the jar to dryness. There can be little doubt 

 that the relative divisibility of the juices of plants and animals must 

 have an important influence on the changes which go on in the c.Mla 

 daring the performance of the functions of the vegetable or animal 

 body. "Thus," observes Dr. Carpenter, "the low diffusibility of 

 albumen obviously tends to the retention of the serous fluids within 

 the tissues ; whilst the high diffusibility of urea will favour iU escape 

 from them." The following is an account of the process of Endosmosis, 

 and some of the conclusions at which we may arrive, from Dr. 

 Carpenter's ' Principles of Physiology : ' 



" If into a tube, closed at one end with a piece of bladder or other 

 membrane, be put a solution of gum or sugar, and the closed end be 

 immersed in water, a passage of fluid will take place from the 

 exterior to the interior of the tube, through the membranous septum ; 

 so that the quantity of the combined solution will be greatly 

 increased, its strength being proportionably diminished. At the 

 same time, there will be a counter-current in the opposite direction ; 

 a portion of the gummy or saccharine solution passing through the 

 membrane to mingle with the exterior fluid, but in much lev 

 quantity. 



" The first current is termed Endosmose, and the counter-current 

 Exosmose. The increase on either side will of course be due to the 

 relative velocity of the currents ; and the changes will continue until 

 the densities of the two fluids are so nearly alike as to be incapable of 

 maintaining it. The greater the original difference (provided that the 

 denser be not actually viscid, but be capable of mixing with the 

 other), the more rapidly and powerfully will the process be performed. 

 The best means of experimenting upon the phenomena is afforded by 

 a tube, narrow above, but widely dilated below, so as to afford a large 

 surface to the membrane, compared with that of the superincumbent 

 column, which will then increase in height with great rapidity. By 

 bending this tube in the form of a syphon, and introducing into it* 

 curve a quantity of mercury, the force an well as the rapidity of 

 the Endosmose between different fluids may be estimated with pre- 

 cision. In this way It was ascertained by Dutrochet, in some of his 

 experiment*, that fluid might be raised against a pressure of no less 

 than 44 atmospheres, or nearly 70 Ibs. to the square inch. Although 

 it is not universally true that the activity of the process depends upon 

 the difference in density of the two fluids (for in one or two cases the 

 stronger current passes from the denser to the lighter), it seems to be 

 so with regard to particular solutions, as those of gummy or saccha- 

 rine matter. No endosmose takes place between fluids which will 

 not mingle, such as oil and water ; and very little between xiu-h 

 a* act chemically on each other. Although an organic membrane 

 forms the best septum, yet it has been found that thin lamina: of 

 baked pipe-clay will suffice for the evident production of the pheno- 

 menon ; and that porous limestones possess the same property in 

 an inferior degree. Although it may not yet be possible to explain 

 all the phenomena of Endosmose upon physical principles, yet these 

 will go so far towards it that the general conditions of the process 

 may be considered as well understood. Supposing that two mutually 

 diffusible liquids are on the opposite sides of a porous septum, which 

 is not equally penetrable by them, then the one which i most readily 

 imbibed will tend to occupy the capillary passages of the septum, and 

 will thus be brought into contact with the liquid on the opposite side. 

 This contact will permit the diffusion of that which has passed through 



