838 THE POPULAR SCIENCE MONTHLY. 



comino- imbued with certain characteristics of that tissue. Hence 

 a difference, a variation, between the parent germs and their off- 

 spring. 



Now, the one characteristic of the tissue which most strikes our 

 attention is its degeneracy, and this degeneracy must exert its influence 

 on the organisms which depend upon it for existence, so that in the 

 thus derived organisms we have the germ vitality and function, plus a 

 certain amount of degenerate tissue characteristic. Germs thus modi- 

 fied and brought into contact with tissue of the same kind, though 

 less degenerate, will, in virtue of this constitutional modification, stand 

 a better chance of establishment thereon, at the same time adding to 

 the degenerate condition with which they meet in the new tissue the 

 characteristics of the degeneracy of tissue they have left. The effects 

 thus produced will be more acute, the constitution of the germs further 

 modified, and their power increased. Hence it is possible to conceive 

 that if by any chance a condition of tissue which could be called per- 

 fectly healthy was to be anywhere met with, even this tissue might in 

 time become subject to the influence of these organisms. Of course 

 tissues may be more or less susceptible to their influence, more or less 

 healthy, but it is more than doubtful whether it can be positively said 

 of any one tissue that it is absolutely healthy, any more than it can be 

 said of the individual man or woman. It is therefore possible to con- 

 ceive that at some time or other there has existed only one kind of 

 germ, that variations from this one type have arisen in consequence of 

 the modification wrought upon different individuals by their chance 

 falling upon this or that degenerate tissue. Variation must lead to 

 specialization, and finally we find diseases all dependent upon the 

 action of germs, as different from one another as one species of animal 

 differs from another. 



But there is another direction in which these germs must have been 

 modified fully to account for the differences we now see. Germs may 

 still exist which have only the power of exciting a simple inflammation 

 in any degenerate tissue. Others, a step more advanced, are found, 

 whose action is more potent, which have attractions for the one special 

 tissue in which they have been bred ; while others are capable of 

 exciting the special form of inflammation in which they have had their 

 origin, in tissues various in structure and composition. This power or, 

 rather, increase of power in other words, further variation in consti- 

 tution thus displayed is only to be accounted for by the supposition 

 that its acquisition is secondary to the act of establishment, and that it 

 is brought about by means of the blood itself receiving some of the 

 germs and conveying them to some other tissue, on which, in virtue of 

 its degeneracy, and possibly of a further modification, they have them- 

 selves received from the blood, they are enabled to effect a settlement. 

 It must also be remembered that their modification, which enables 

 them to select a tissue for their primary and more virulent action, 



