J. Jackson Clarke, Observations on the Histology of Cancer. 281 
Observations on the Histology of Cancer. 
By 
J. Jackson Clarke, M.B. Lond. F.R.C.S., 
Patbologist to St. Mary’s Hospital and Assistant-Surgeon 
at the North-West London Hospital. 
With 1 plate. 
The question of the presence and meaning of sporozoa in 
malignant growths increases in interest and the debates regarding 
the distinctive marks of the bodies which different authors regard as 
sporozoa seem no nearer a conclusion than they were two years ago. 
Thus, although I have elsewhere *) briefly expressed my views, I 
tliink it may not be out of place if I give in more detail than I have 
hitherto been able to do, sorae of the data on which I have based 
certain conclusions. 
About 70 epidermoidal cancers, which I have examined, gave me 
in every instance the same results, but in one of these growths owing 
to its looser texture the contrast between the heterologous (parasitic) 
and the homologous or tissue-cells, was more marked and hence I have 
selected this growth as the source of the illustrations, though all I 
have to say applies equally to all the growths I examined. 
A lobulated tumour as large as a chestnut was removed by my 
friend Dr. Scanes Spicer from the front of the septum of the 
nose of a man aged eighty. In the pathological report on the growth 
written in May 1892 I stated that the tumour was a squamous 
epithelioma and contained large numbers of sporozoa. I came to the 
conclusion that growth had its origin in the skin of the columna 
nasi. The sporozoa I recognised in the sections were identical in 
all their more important features with the psorosperms I had pre- 
viously described 1 2 ) in the human kidney and ureter, I subsequently 
found that in some of their phases the parasites were identical with 
those originally described by L. Pfeiffer 3 ) and with those described 
by L. Wickham 4 ), and in other of their phases they are identical 
with some of the bodies, figured by Korotneff 5 ) and Kurloff 6 ). 
In preparing the sections a great variety of stains were used 
but for convenience of illustration and for other reasons which will 
appear I will with one exception confine myself to bodies as seen in 
sections well-stained with the Biondi-Ehrlich-Heidenhain 
reagent. 
The various cell-inclusions abundantly present in every section 
I have described sufficiently elsewhere and I will not occupy space 
by further description but will confine myself to the bodies which in 
1) Jackson Clarke, Morbid growths and sporozoa. London 1893. 
2) Jackson Clarke, Transactions of the Pathological Society of London. 1892. 
3) L. Pfeiffer, Protozoen als Krankheitsesreger. 1891. 
4 ) L. Wickham, Psorospermoses cutandes. Paris 1890. 
5) Korotneff, Centralblatt für Bakteriol. u. Paras. 1893. Mar. 
6) Kurloff, ibid. 1894. Mar. 
