PROTOPLASM. 7 



capacity of chemically building up material for its own use 

 from the food taken in. Protoplasm has an alkaline 

 reaction, is readily dissolved by a weak solution of hydrate 

 of potash (KHo), but not by a concentrated solution. 



{b) Physical. — A peculiar and universal property of proto- 

 plasm is its power of movement. In the case of naked 

 protoplasm, that is, protoplasm that has not enclosed 

 itself in a more or less rigid protective external coating or 

 cell-wall, spontaneous movement is often very marked, as 

 illustrated by the antherozoids or fertilizing bodies of the 

 mosses and ferns, which consist of a minute mass of proto- 

 plasm furnished with one or two cilia or slender hair-like 

 prolongations which act as organs of locomotion, propelling 

 the antherozoid through water at a rapid rate, or in the 

 more sluggish movement of the organism known as 

 " flowers of tan " {Fuligo varians), one of the Myxogastres, 

 the protoplasm of which is frequent amongst the tan in 

 conservatories, resembling rather thin mustard in colour and 

 consistency as it creeps about. Protoplasm even when 

 enclosed within a rigid membrane can be shown in many 

 instances to possess the power of movement; as seen in the 

 cells of stonewort (Nitella), American water-weed {Ana- 

 charis canadensis), &c. If watery protoplasm is heated to 

 above 50° C. ( = 122° F.), coagulation or stiffening takes 

 place and death is the result, in this respect agreeing with 

 albuminoids, as white of egg for example. Dilute mineral 

 acids and alcohol also cause coagulation in protoplasm. 



Electric shocks of moderate strength cause protoplasm 

 to contract at once ; this contraction may be considered 

 as the commencement of coagulation from which the pro- 

 toplasm recovers. Strong shocks induce permanent coagu- 

 lation, and consequently, death. Living protoplasm does 



