THE CHARACTERISTICS OF ORGANISMS 13 



years ago (1891), republished in The Birth-Time of the World (1915), 

 Prof. Joly laid emphasis on the organism's power of accumulating 

 energy. The more heat energy is put into an iron bar, the more 

 difficult it becomes to get in more, and the more readily does some 

 of the heat radiate out. But it is different with the living creature ; 

 it absorbs energy acceleratively and accumulatively. Prof. Joly 

 puts the case tersely: 



"The transfer of energy into any inanimate material system is 

 attended by effects retardative to the transfer and conducive to 

 dissipation. The transfer of energy into any animate system is 

 attended by effects conducive to the transfer, and retardative of 

 dissipation. . . . The animate system is aggressive on the energy 

 available to it, spends it with economy, and invests it with interest, 

 till death finally deprives it of all." 



Colloidal Protoplasm. — ^The accumulation of energy in organ- 

 isms is mainly effected by storing complex chemical substances, 

 not merely as reserves in the ordinary sense, like the plant's starch 

 and the animal's fat, but in the living substance itself in the form 

 of increased protein material. The chemical formula of egg-albumin, 

 to take a familiar protein, is often given as Ci42 8H^244N3640462Si4; and 

 this hints at the complexity of these substances. In the strict sense, 

 protein material dees not form definite stores in animals, though 

 it is a common reserve in the seeds of plants, but it accumulates 

 as the amount of living matter increases. The potential chemical 

 energy of the complex carbon-compounds found in, living cells is 

 particularly valuable because the living matter occurs in a colloidal 

 state. Of this it is enough in the meantime to say that a watery 

 "solution" holds in suspension innumerable complex particles, too 

 small to be seen, even with the microscope, but large enough to have 

 an appreciable surface. The particles do not clump together or sink 

 because each carries an electric charge, and like charges repel one 

 another. Even a metal like gold can be readily made to assume 

 this colloidal form. In some colloids, however, as may be illustrated 

 by liquid gelatine, the particles are, as it were, protected by a coat 

 of water molecules, and such particles are spoken of as "emulsoid", 

 in contrast to "suspensoid", as in the case of liquid gold. But every- 

 one knows that the cooled gelatine sets, the "sol" becoming a 

 "gel". In this state the particles adhere to one another and give 

 some rigidity to the whole. The alternation of "sol" and "gel" 

 plays, as we shall see, an important part in vital processes. 

 Proteins always present themselves in the colloidal state in living 

 organisms, and it is clear that they thus afford, in their in- 

 numerable particles, a large surface on which chemical and physical 

 changes can take place. 



Specificity. — Each kind of organism has its chemical indi- 

 viduality, implying a specific molecular structure in some of the 



