The Microscope. 199 



are pretty well agreed that a more or less similar reticulum is 

 demonstrable in the protoplasm of plants. Prof Goodale seems 

 to have no doubt on this point, although he thinks that ' this 

 conception of protoplasm as a mass composed of a net-work of 

 minutest fibres enclosing in the meshes another substance, pre- 

 sents . . . great difficulties when we endeavor to explain the 

 movements within the cell,' and that ' it is very difficult to ex- 

 plain in any way the so-called wandering of protoplasm outside 

 the cell-wall or into intercellular spaces.' 



" Dr Heitzmann, however, considers the reticulum or mesh an 

 easy explanation of protoplasmic movements. To him the net- 

 work of living, contractile matter contains in its interstices a life- 

 less liquid, which, by its contraction, it is able to squeeze out of 

 itself, or from one part to another. Thus, he "says, 'the liquid 

 held in the meshes, being driven out of the contracted portion, 

 will rush into a portion at the time at rest, and will extend this 

 portion in the shape of what has been termed pseudopodia.' 



" In the work from which I have just quoted (Microscopical 

 Morphology, New York, 1883), Dr Heitzmann generalizes as fol- 

 lows : ' What . . . was called a structureless, elementary organ- 

 ism, a 'cell,' I have demonstrated to consist only in part of liv- 

 ing matter, while even tjie minutest granules of this matter are 

 endowed with manifestations of life. The cell of the authors, 

 therefore, is not an elementary, but a rather complicated, organ- 

 ism, of which small detached portions will exhibit amoeboid 

 motions. . . How complicated the structure of a minute par- 

 ticle of living matter may be we can hardly imagine ; what we 

 do know is that the so-called ' cell ' is composed of innumerable 

 particles formerly attributed to the cell-organism.' 



" It having been shown that life hangs upon a web of infinite 

 tenuity, and does not reside necessarily in either a vesicle or a 

 lump, it was a natural and easy step to extend this network from 

 tissue to tissue and organ to organ, in an unbroken circuit of 

 vital communication. This step Dr Heitzmann does not hesi- 

 tate to take, for says he, ' There is no such thing as an isolated, 

 individual cell in the tissues, as all cells prove to be joined 

 throughout the organism, thus rendering the body in toto an in- 

 dividual. What was formerly thought to be a cell is, in the 

 present view, a node of a reticulum traversing the tissue. . . 

 The living matter of the tissues exists mainly in the reticular 



