8j8 the popular SCIENCE MONTHLY. 



similar condition, since they probably penetrate the cells as minute 

 fibrils. 



C. Heitzmann, a skilled microscopist, now of New York, has long 

 maintained, and has recently reiterated, a theory which declares that 

 this fibrillar extension is not confined to epithelial and ganglion cells, 

 but is common to all the cells of the body, and that intimate intercon- 

 nections between all the cells and tissues are thus made. Even the 

 bony structure he declares to be everywhere permeated by fine chan- 

 nels, in which run fibrils of protoplasm, connecting the granular and 

 nuclear masses throughout the whole substance. He, indeed, denies 

 the existence of separate cells, and claims that the body is simply a 

 vast reticulum, with nuclear masses as nodes of the network. Instead 

 of being composed of numerous separate amoeboid cells, it is a single 

 complex amoeba. 



This bioplasson theory is not accepted by microscopists generally, 

 and it certainly goes too far in denying the existence of distinct cell- 

 structures. It, may be possible that it indicates a final stage in the 

 process of cell-evolution. Distinct isolated cells undoubtedly exist in 

 the blood and lymph fluids of the body. But in the more solid tissues 

 this isolation is, in some cases at least, replaced by an interconnection 

 of cells through the medium of inosculating fibrils. And it is quite 

 possible that this fibrillar extension becomes so declared in extreme 

 cases as to produce the appearances described by Heitzmann. The 

 basis or ground-substance of the outer cell of osseous tissue may be 

 converted, by deposition of lime-salts, into bony matter, through which 

 the fibrils extend from the nuclei in open channels. If this theory be 

 correct, the original cell becomes a nuclear center of active protoplasm 

 ajid an outer region whose ground-substance is converted into bone, 

 while its protoplasmic fibrils extend until they join similar fibrils of 

 other cells, thus converting the whole mass into a living network 

 whose interspaces are occupied with bone. 



In other tissues a similar condition may exist, the bony matter of 

 the osseous ground-substance being represented by other inactive 

 material proper to the tissue. Perhaps every phase of differentiation 

 exists, from the completely isolated corpuscles of the liquid tissues to 

 the complete and extended reticular structure described as existing in 

 bone. 



This theory naturally leads to some probable speculative views. 

 If, as seems evident, the nerve-fibers originate in such extensions of the 

 intercellular network, possibly the fibrils of individual cells have a con- 

 ductive or nerve function, as also the contractile or muscle function 

 which some writers ascribe to them. Their extension from cell to cell 

 would indicate nerve communication, and it may be that the un- 

 doubted nerve and muscle function of many low animals, in which no 

 nerves and muscles have been discovered, may be due to these inter- 

 lacing fibrils. And the widely extended nerve-system of the higher 



