82 J. B. CLELAND. 
sulting. From the account, it is possible that this was 
a case of rat-bite fever, the cat having been infected with 
the spirochetes from catching rats. 
A Theory as to the Nature of Cancerous Processes. 
During recent years great progress has been made in un- 
ravelling the principles governing phylogeny, ontogeny 
and heredity. In one direction, the discovery of the chro- 
mosomes of cells and of the differences between those of 
somatic and those of gametogenic cells, and in another 
direction the Mendelian theory of heredity, have both led 
to far-reaching advances in our knowledge of life-processes. 
Having been engaged some years ago in cancer investiga- 
tions as Cancer Research Scholar at the London Hospital, 
and this at a time when, through the researches of Farmer, 
Moore and Walker, particular attention was being directed 
to the types of mitoses found in cancer eells, my attention 
was naturally especially focussed on this aspect of the 
question. Since then opportunities for further practical 
work on this subject have not presented themselves to me, 
but nevertheless my interest in this and allied questions has 
naturally not flagged, and has been stimulated from time 
to time by new views and ideas that have suggested them- 
selves, often as a result of collateral work by various in- 
vestigators. The present seems a fitting occasion to pre- 
sent these ideas, partly because some of them may be of 
interest to educated people in general, partly because they 
may help in the solution of problems still unsolved. 
A cancer is a new growth or neoplasm. Neoplasms may 
be roughly divided into two groups, innocent and malig- 
‘nant. Innocent growths form tumours, whose cells grow 
independently, or relatively so, of the needs of the rest of 
the body. Their cells do not invade the adjacent tissues, 
and injury or death to their host results merely from their 
position and size, which may interfere with vital functions. 
