THE 
MAIOTIC 
PROCESS IN MAMMALIA 
J. E. S. MOORE, A.R.C.S., F.L.S 
OF THE CANCER RESEARCH LABORATORIES, UNIVERSITY OF LIVERPOC 
AND 
C. E. WALKER, F.L.S 
ihe objects of the present communication are to give as complete and 
accurate an account, as our present methods will permit, of the maiotic 
phenomena in mammals: that is to say, of the successive changes which take 
place during the transformation of pre-maiotic, or somatic, into sexually re- 
productive cells. 
The reasons which make such an undertaking desirable are numerous. 
In the first place, the existing observations bearing upon the matter 
are at present widely scattered, both as regards the portions of the 
maiotic process they refer to, as well as with respect to the types from 
which the illustrations have been drawn. In fact, curious as it may seem, so 
far as we are aware, no complete account of the maiptic phenomena in any 
mammal exists at the present time. The researches of Meves, Borst, Ebner, 
ourselves, and others have dealt with individual sections of the process, with 
the origin of the archoplasmic vesicle ; the history of the centrosomes in rela- 
tion to the Spermatozoa ; the existence of heterotype and homotype divisions, 
and the like. But in no existing publication has the whole maiotic process 
been followed out. In the conjoint work by one of us* and Professor Farmer, 
the maiotic divisions in mammals were briefly referred to, as coming into the 
general scheme we were then able to formulate regarding the maiotic process 
in animals and plants ; but the matter was necessarily dealt with in the 
briefest possible manner, and no attempt was made to indicate in detail the 
wide divergence which exists between the new interpretation of the processes 
involved, and the older conceptions regarding the heterotype division, con- 
tained in the works of Flemming and others. 
It would thus not be undesirable that a full account of our observations 
upon mammalia should be published merely as a supplement to our former 
work. But beyond this, the fact that certain features peculiar to the maiotic 
change have been found by ust to occur as constant cytological peculiarities 
■during the development of malignant growths in man, renders the details of 
the maiotic change in mammals particularly important at the present time. 
The formation of archoplasmic vesicles in mammalian sexual cells deserves 
special attention, for these very definite objects have been shown to be 
* The maiotic Phase (Reduction divinus) in Animals and Plants. Quart. Journ. Micro. Sci., Vol. 48, 1904. 
f J. B. Farmer, J. E. S. Moore, and C. E. Walker. Pro. Roy. Soc, 1903. 
Note. — At the last moment we have received a copy of a paper by Prof- F. A. Janssens, " Evolution 
■des Auxocytes Males du Batracoseps Attenuatus." We regret that it is at present impossible to deal with 
this row, though it will be seen that we differ from him mateiially 1'por. some important points. At least 
one important stage described by us has not been recognised by Prof. Janssens. 
