THE 



POPULAR SCIENCE 

 MONTHLY. 



OCTOBER, 1879. 



PEOTOPLASM AND LIFE.* 



By Professor G. J. ALLMAN, LL.D., F.K.S., 



PRESIDENT OF THE BRITISH ASSOCIATION. 



MORE than forty years have now passed away since the French 

 naturalist, Dujardin, drew attention to the fact that the bodies 

 of some of the lowest members of the animal kingdom consist of a 

 structureless, semi-fluid, contractile substance, to which he gave the 

 name of Sarcode. A similar substance occurring in the cells of plants 

 was afterward studied by Hugo von Mohl, and named by him Pro- 

 toplasm. It remained for Max Schultze to demonstrate that the sar- 

 code of animals and the protoplasm of plants were identical. 



The conclusions of Max Schultze have been in all respects con- 

 firmed by subsequent research, and it has further been rendered cer- 

 tain that this same protoplasm lies at the base of all the phenomena of 

 life, whether in the animal or the vegetable kingdom. Thus has arisen 

 the most important and significant generalization in the whole domain 

 of biological science. 



Within the last few years protoplasm has again been made a sub- 

 ject of special study ; unexpected and often startling facts have been 

 brought to light, and a voluminous literature has gathered round this 

 new center of research. I believe, therefore, that I can not do better 

 than call your attention to some of the more important results of these 

 inquiries, and endeavor to give you some knowledge of the properties 

 of protoplasm, and of the part it plays in the two great kingdoms of 

 organic nature. 



As has just been said, protoplasm lies at the base of every vital 

 phenomenon. It is, as Huxley has well expressed it, "the physical 

 basis of life." Wherever there is life, from its lowest to its highest 



* Inaugural Address at the Sheffield meeting, August 20, 18*79. 



VOL. XT. 46 



