142 PHYSIOLOGICAL BOTANY. 



act an important part. Their formation depends upon the de- 

 composition of carbonic acid (CO 2 ), the retention of the carbon, 

 and the exhalation of the oxygen under the stimulus of the light. 

 If the formation of cellulose continue beyond the present need 

 for cell formation, the excess is deposited in the form of starch 

 granules enclosed within the globules of chlorophyl, one in each. 



444. When the starch granules are redissolved, they go to incrust the next new cell, or 

 to form a secondary layer in the old cell ; or in Autumn they go out into the general cir- 

 culation, and are at length stored up in the buds, the cambium, the roots, ready Tor 14 

 early use the following Spring. 



445. The increase of the protoplasm from the decomposition of the ammonia or other 

 nitrogenous compounds present, is a more intricate process, but no less evident; and 

 when in excess, this also is deposited in minute globules of gluten, mucus, legumine, 

 chiefly in seeds (Wheat, Beans, Rice), in aid of germination. 



446. The starch and gluten deposits of the Wheat-kernel are about sixty-eight and 

 seventeen per cent. The former is found in the interior cells, the latter in the exterior, 

 adjoining the pericarp or bran. In "flouring," some of the gluten adheres to th bran, 

 and some constitutes the coarser meal, all of which is separated by the "bolt." Extra 

 flour must, therefore, necessarily be deficient in gluten, the only element of the Wheat 

 which adapts it to the formation of muscle a great error. 



Review. 436. What inquiries next arise? 437. A problem unsolved. What the phe- 

 nomena of plant life? 438. What the lowest form of life ? Whence does it spring ? Why 

 subordinate? 439. The process of vegetation. The five vital phenomena. 440. Two 

 kinds of organic matter. Write out their symbols. Which resembles animal matter? 

 441. \Vhatthe cell imbibes. From what fluid? 442. The chemical decomposition Ex- 

 press it. What becomes of the cellulose thus formed? 443. C'hlorophyl how formed? 

 Whai globule within a globule ? 445. What becomes of the excess of protoplasm ? 440. 

 Whf.t per cent, of starch and gluten in Wheat ? Why is extra flour deficient in gluten ? 



7 



CHAPTER VII. 



FERTILIZATION. 



447. Such being the vital energy of the cell, it is easy to admit 

 the possibility of either its solitary existence as a plant (Proto- 

 coccus, etc.), or of its associated existence, as in the living tissue 

 of most plants. Now all plants, without exception, do actually 

 commence existence in the state of a simple cell. But while in 

 the lower plants (Cryptogamia) this simple cell, the plant rudi- 

 ment, is at once discharged, free and independent, to float or 

 grow, in the Phenogamia it is yet a while protected and nour- 

 ished by other cells the cells of the ovule. 



448. This primitive cell-plant, after acquiring the requisite 

 means, swells and divides itself into two or more new cells. If 



