260 PLANT AND ORGANIC CHEMISTRY 



sarily be included in a study of plant life. Whether this life 

 reveals itself in the perfume of sweet flowers, or in the mani- 

 fold forms of vegetation, from the simple mass of plant- jelly 

 to the majestic forest- tree, its dependence upon matter invokes 

 the most eager desire to acquaint ourselves with its various 

 manifestations. 



When matter, through chemical change, exhibits properties 

 of absorption, metabolism, excretion, reproduction, contractil- 

 ity, automatism, and irritability, it is said to be living. In this 

 condition it is called protoplasm. This substance is very com- 

 plex and of undetermined composition, though its proximate 

 constitution is known. 1 It is always present where life, as de- 

 fined, is found, apparently the same in the lower as in the 

 higher plants. 



The lowest forms of plants, plasmodia, are irregular-shaped 

 masses of jelly, undifferentiated in form, function, and chemical 

 composition. This living jelly is described "as a colloidal 

 albuminoid united with more or less water." 2 



Plant cells, when alive, are composed of a semi-fluid albumi- 

 nous substance very like plasmodia, closed on all sides, with 

 a watery liquid holding salts and saccharine substances in 

 solution, and lying in contact with a firm elastic membrane 

 called the cell wall ; also, like it, closed on all sides, and con- 

 sisting of cellulose, water, and inorganic matter. Some of 

 the Algae and all higher plants are congregations of these 

 cells grouped as tissues and organs, and their albuminoid 

 contents are undergoing continual change; in life it is a 

 building-up process, the food being supplied from the gases, 

 water, and inorganic substances of the surroundings, and 

 elaborated in the plant's own laboratory to meet its needs. 



The vegetable kingdom does not usually claim our atten- 

 tion for its intellectual attainments, although its members 

 would certainly seem to possess greater chemical skill than 

 a higher race of beings exhibit in their laboratories. Some 

 few of this higher race are "going to take lessons" how to 



1 Reinke and Rodewald, Berlin, 1881; Physiological Botany, by G. L. 

 Goodale, 1885, p. 197. 



2 T. Sterry Hunt, Min. Phys. and Physiography. 



