1889. J BOTANICAL GAZETTE. 24 I 



chants, the latter has demonstrated the relations of a part of 

 this irritability of protoplasm to its physical constitution. 

 But, as a result of all these recent studies, it becomes more 

 and more clear that the chemical relations of the proto- 

 plasmic activities are still veiled in mystery. Botanists are 

 receding from a position held by many only a few years ago, 

 namely, that it is safe to use the words albuminoids and pro- 

 toplasm interchangeably ; nowadays the latter term is gener- 

 ally restricted to morphological and physiological concep- 

 tions, the former keeps its wide chemical significance. 



Just here come in the chemical studies of protoplasm ; by 

 Rodewald and Reinke on a large scale, by Loew and !><>- 

 korny, and by Schwarz under the microscope. All of these 

 results compel us to recognize in protoplasm a substance of 

 bewildering complexity of composition and constitution. 

 Moreover, you all know r how wide this held of research 

 has suddenly become by the discovery that different microbes 

 (which are, essentially, minutest masses of protoplasm) not 

 only give .rise to such diverse products, among others the 

 ptomaines, but present such diverse chemical reacitons. 



Protoplasm is no longer regarded by any one in any 

 sense as a comparatively simple substance. 



The third thesis, namelv, protoplasm has no demonstrable 

 structure, has been modified in a striking manner as a result 

 of improved appliances for research. By better methods of 

 staining, and by the use of homogeneous immersion objectives, 

 the apparently structureless mass is seen to be made up of 

 parts which are easily distinguishable. There has been, and 

 in fact is now, a suspicion that some of these appearances, 

 under the influence of staining agents, are post-mortem 

 changes and do not belong to protoplasm in a living state. 

 But it seems to be beyond reasonable doubt that protoplasm 

 is marvellously complex in its morphological and physical 

 as well as its chemical constitution. One statement of the 

 case is as follows : 



Under ordinarv circumstances, protoplasm is composed 

 of a mesh of inconceivable fineness, in which mesh are en- 

 tangled the more liquid interfilar portions (paraplasma) ; so 

 that the dry husks left in Reinke's experiment may be re- 

 garded as the residue of network from which all the moisture 

 has been expelled. But this conception of protoplasm as a 

 mass composed of a network of minutest fibers enclosing in 

 the meshes another substance, presents, as has been well 

 shown by some critics, great difficulties when we endeavor 



