12 CONTENTS OF CELLS. 



Marvel of Peru, and in the sepals of the strawberry ; numerous 

 acicular crystals have been observed in Fuchsias, and solitary cubical 

 crystals in the superficial cells of the sepals of 

 ^ ^j, ^ •■ Prunella vulgaris and Dianthus Caryophyllus. 



^^^te^^^N— t^/ In the outer covering of the seed of Ulmus 

 yMi^^M^^" campestris, the sinuous boundaries of the ■ 

 " "^^^8^^^ compressed cells are traced out completely by 

 "^^' ^r.'^^) minute rectangular crystals adhering to each 

 ^^te^^fer^ '' other. linger detected oxalate of lime crystals 

 ' '^^^s^^y^ in Ficus indica and Calathea zebrina. Accord- 

 ' . ing to Dr. Gulliver the presence or absence of 



'^' ■ raphides may be used for distinguishing certain 



natural orders. He says that Balsaminacese, Onagracese, and Galiacese, 

 may be specially called Kaphis-bearing orders. In the epidermal cells of 

 many Urticacese concretions of carbonate of lime (cystoliths) are found.* 

 Chlokophyll (%Xw|i)s, green, and ^vXXov, a leaf), or the green 

 colouring matter of plants, floats in the fluid of cells, accompanied by 

 starch grains. It difiers from starch in being confijied to the super- 

 ficial parenchyma, and in being principally associated with the phe- 

 nomena of active vegetable life. It has a granular form (fig. 39, u ; 

 42, c), is soluble in alcohol, and is developed under the agency of light. 

 It is well seen in leaves. Under the influence of darkness it under- 

 goes changes which are seen in the phenomenon of blanching or etiola- 

 tion. Its granules are usually separate, but sometimes they unite in 

 masses (fig. 37, c). Stokes says that the chlorophyll of land plants 

 consists of four substances, two green and two yellow, all possessing 

 highly distinctive optical properties. The green substances yield 

 solutions exhibiting a. strong red phosphorescence ; the ySUow sub- 

 stances do not. These substances are soluble in the same solvents. 

 Green sea-weeds agree with land plants. Eed sea-weeds in addition 

 to chlorophyll contain a red colouring matter of an albuminoid nature. 

 Chlorophyll is important in a physiological point of view. It is 

 developed under the influence of light, and the granules exhibit 

 marked movements, as have been observed in the leaves of some 

 mosses. Chlorophyll gives a black band in the red of the spectrum. 

 Green vesicles or granules allied to chlorophyll are found in some of 

 the lower animals, as Hydra viridis. Other kinds of colouring matter 

 are also produced during vegetation, and occur in the form of fluids or 

 of granules in the interior of cells. 



Oils and Resinous mattee are found in the interior of cells, as well 

 as in intercellular spaces. The cavities containing them are denomi- 

 nated cysts, reservoirs of oil, and receptacles of secretions. They are easily 



Kg. 42. Cellular tissue of Colooasia odora. c c. Cells with grains of ohlorophyU. 

 rrrr, Baphidian cells projecting into a lacuna or intercellular space. 



* See Papers by Dr. Gulliver, in the Annals of Natural History, 3d ser. xv. et seq. 



