I 4 PROTOPLASM. 



periplastic substance was formed. Next he may discover 

 that the endoplast is of the highest importance instead of 

 no importance at all, and then there is an easy step to the 

 doctrine that the periplastic substance is formed by and from 

 the protoplasm which has properties and "subtle influences''' of 

 a remarkable kind, but is not endowed with the absurd fiction 

 of vitality. 



Max Schultze included under the head of protoplasm 

 the active moving matter forming the sarcode of the Rhizo- 

 pods as well as the substance circulating in the cells of 

 vallisneria, the hairs of the nettle, and other vegetable cells ; 

 and now it is generally admitted that the active, moving 

 matter constituting the white blood-corpuscle, the mucus 

 and pus corpuscle, and other contractile bodies widely dis- 

 tributed, is essentially of the same nature. The move- 

 ments characteristic of this matter have been attributed to 

 an inherent property of contractility ; and this property 

 has been held by some to be characteristic of, and peculiar 

 to, protoplasm. Kiihne considers all contractile material 

 to be protoplasm, and includes the different forms of 

 muscular tissue in the same category as the matter of the 

 amoeba, white blood-corpuscle, &c. But if we apply the 

 term protoplasm to the contracting muscular tissue which 

 exhibits structure, as well as to the living moving matter of 

 the amoeba, &c., in which no structure at all can be made 

 out, it is obvious that these must be regarded as essentially 

 different kinds of protoplasm, 'because they differ in proper- 

 ties which are essential and of the first importance. The 

 contractile movement of the amoeba, white blood-cor- 

 puscle, &c., is a phenomenon very different from the con- 



