of Edinburgh, Session 1884-85. 
269 
3. Vital Eelations of Micro-Organisms to Tissue Elements. 
By G. Sims Woodhead, M.D., and Arthur W. Hare, 
M.B. Communicated by Professor Turner. 
In entering upon the consideration of a subject so important, 
one cannot but feel surprised at the very general obscurity which 
envelops a question upon which so large a mass of accurate detail 
has been collected. In looking for the cause of this unsatisfactory 
state of affairs, it would appear to be due to a lack of appreciation 
by one set of workers, of the methods pursued by another, and this 
in two directions. In the first place, the student of normal cell life 
relegates aberrant vital processes entirely to the domain of pure 
pathology ; whilst the pathologist, relying mainly on organs as a 
whole for his views on function, normal and abnormal, is apt to 
ignore the value of the study of the cell processes as carried on 
under normal conditions. How without the aid of such study are 
we to explain inherited variability in cells? How without its aid 
can we interpret aright the numerous processes which, minute or 
almost imperceptible in the unit, in the aggregate, constitute a 
disease? Conversely, how is the student of cell life to make a 
complete analysis of normal vital phenomena if he fails to contem- 
plate the striking analogies presented in morbid conditions? Mr 
Geddes, in a paper on the cell theory, read before this Society in 
1883, attempted to remove this reproach on the one hand, whilst 
on the other there are already signs of a growing recognition among 
pathologists of the claims upon their attention of those fundamental 
vital phenomena of cells so fully expounded by Goodsir and 
Virchow. 
For our present purposes it will be necessary to quote merely a 
definition of pathological changes in cells as “those variations 
which happen not to be conducive to success in the struggle for 
existence.” Taking the theory that “ variation and disease in the 
cell are closely allied,” to start from, it will be curious to observe 
how the cycle in cell life, or parts of it, may be traced in those 
processes which are initiated through the action upon them of 
micro-organisms. 
That such a “ variation” theory of disease is now largely held is 
