4:2 LECTURE I. 



ries in it also, so that certain districts belong to one cell, 

 and certain others to another. Yow will see how sharply 

 these boundaries are denned by pathological processes 

 (Fig. 129), and how direct evidence is afforded, that any 

 given district of intercellular substance is ruled over by 

 the cell, which lies in the middle of it and exercises 

 influence upon the neighbouring parts. 



It must now be evident to you, I think, what I under- 

 stand by the territories of cells. But there are simple 

 tissues which are composed entirely of cells, cell lying 

 close to cell. In these there can be no difficulty with 

 regard to the boundaries of the individual cells, yet it is 

 necessary that I should call your attention to the fact 

 that, in this case, too, every individual cell may run its 

 own peculiar course, may undergo its own peculiar 

 changes, without the fate of the cell lying next it being 

 necessarily linked with its own. In other tissues, on the 

 contrary, in which we find intermediate substance, every 

 cell, in addition to its own contents, has the superin- 

 tendence of a certain quantity of matter external to it, 

 and this shares in its changes, nay, is frequently affected 

 even earlier than the interior of the cell, which is ren- 

 dered more secure by its situation than the external 

 intercellular matter. Finally, there is a third series of 

 tissues, in which the elements are more intimately con- 

 nected with one another. A stellate cell, for example, 

 may anastomose with a similar one, and in this way a 

 reticular arrangement may be produced, similar to that 

 which we see in capillary vessels and other analogous 

 structures. In this case it might be supposed that the 

 whole series was ruled by something which lay who 

 knows how far off ; but upon more accurate investiga- 

 tion, it turns out that, even in this chainwork of cells a 

 certain independence of the individual members prevails, 

 and that this independence evinces itself by single cells 



