1898-99. | ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS. 439 
ON THE CYTOLOGY OF NON-NUCLEATED ORGANISMS, 
By A. B. MACALLUM, M.A., M.B., PH.D., 
Professor of Physiology in the University of Toronto. 
(Read May 6th, 1899.) 
In the following pages I have endeavoured to describe the results of 
observations which I have made during the last five years on the 
structure of certain types of non-nucleated organisms. These studies 
are not as complete as I would wish them to be, especially in the case of 
Bacteria, for only a few of the forms of the latter accessible to me were 
of sufficient size to enable me to employ all the micro-chemical methods 
used in the case of the Cyanophycee and Saccharomyces, but the 
results described may prove of service to other investigators in the same 
line, and at the same time stimulate the employment of comprehensive . 
methods of technique in the study of non-nucleated organisms. It is 
doubtful if the ordinary or more complicated methods of staining which 
have been used in this department give results which are of the morpho- 
logical value possessed by results obtained in this way in more highly 
specialized animal and vegetable cells. The existence of a nucleus in 
these low forms of life, if not denied by the great majority of observers 
is at least in dispute. If it is absent what takes its place ? Is chromatin 
present or does there exist in them an analogous substance? As there 
are in many animal and vegetable cells other substances which may take 
up dyes, more especially of the aniline kind, it is obvious that staining 
methods alone are not sufficient to enable the observer to determine the 
solution of questions like these in regard to the lowest forms of life. A 
more satisfactory determination of such questions can be made only with 
methods which comprehend micro-chemical reactions of definitely 
ascertained. values. 
It may be pointed out also that it is in these low forms of life that we 
must look for a key to the secret of the origin of the cell nucleus, as well 
as for data to determine the morphological character of the primal life 
organism. It is of course suspected by many that in Saccharomyces the 
