24: TEE HUMAN BODY. 



animalcules, pass when dried slowly at a low temperature; 

 the drying acting by checking the nutritive processes, 

 which would otherwise have prevented the reattainment 

 of molecular equilibrium. All signs of movement or other 

 change disappear under these circumstances, but as soon 

 as water again soaks into their substance and disturbs the 

 existing condition, then the so-called (( spontaneous" mcYe- 

 ments recommence. If, therefore, we use the term spon- 

 taneity to express a power in a resting system of particles of 

 initiating changes in itself, it is possessed neither by living 

 nor not-living things. But if we simply employ it to desig- 

 nate changes whose primary cause we do not recognize, and 

 which cause was in many cases long antecedent to the 

 changes which we see, then the term is unobjectionable and 

 convenient, as it serves to express briefly a phenomenon 

 presented by many living things and rinding its highest 

 manifestation in many human actions. It then, how- 

 ever, no longer designates a property peculiar to them. A 

 steam-engine with its furnace lighted and water in its 

 boiler may be set in motion by opening a valve, and the 

 movements thus started will continue spontaneously, in the 

 above sense, until the coals or water are used up. The dif- 

 ference between it and the living cell lies not in any spon- 

 taneity of the latter, but in its nutritive powers, which 

 enable it to replace continually what answers to the coals 

 and water of the engine. 



Protoplasm. Finding all these properties possessed by 

 a simple nucleated cell, we are naturally led to inquire upon 

 what part of it do they depend? It is clear that if they are 

 exhibited in the absence of any one it cannot be essen- 

 tial to their manifestation. Now a study of the lower] 

 forms of life shows us that these powers are independent or 

 the cell nucleus, since we find them all exhibited by cells in 

 which the nucleus is wanting. Moreover, in many cases 

 not only the nucleus but all granules are absent, and yet wo 

 find the remaining mass nutritive, reproductive, irritable, 

 contractile, conductive, co-ordinative, and automatic. We 

 are thus driven to conclude that in the case of the granular 

 blood-cells, these faculties are most probably endowments 



