812 J. Jackson Clarke, 
which portions of the parasite are separating. Some of these sepa- 
rated fragments are nacleated others have the characters of the dod- 
nucleated parasites described above. Many of the parasites both 
free and iDtracellular show a condition resernbling that depicted in 
fig. 10, which recalls boclies such as the upper of the two from the 
squaroous epithelioma I depicted in Fig. 6. Taf. 3 Centralbl. für 
Bakt. 1894. Aug. 25. In some of the parasites structures giving a 
metachromatic nuclear reaction and strongly resernbling sickles are 
present. This is shown in fig. 11 and has been previously delineated 
by Pawlovsky, loc. cit. fig. 44. I must here recall the fact that 
I consider the sickle-form as not essential in the swarm-spores of 
sporozoa and would instance their absence in the psorosperms of the 
ureter. Finally I would refer to the process I interpret to be swarm- 
sporing, the result of processes such as those shown in figs. 8 and 9 
of this article and of others such as I have depicted elsewhere 1 ) 
and which are evidently of the nature of mitosis. The process I 
refer to is evident in sarcomata of the most varied types but is 
most unmistakable in the round-celled growth of the testis to which 
I have already referred and thus I will take it as the source of the 
illustration, fig. 12, which represents the result of the subdivision of 
a free parasite into minute bodies some of which present bars of 
chromatin others are small and dense and the larger ones by com- 
parison with neighbouring groups are seen to be destined to undergo 
further subdivision. Bodies similiar to the subdivisions of this 
body which I regard as a sporozoon in the act of swarm-sporing 
are sometimes to be found in the nuclei of sarcoma-cells and fre- 
quently in the cell-protoplasm as figured above. 
These bodies satisfy the conditions which I think justify the 
conclusion that they are sporozoa: they agree in their main cha- 
racteristics with the different stages of recognised sporozoa, e. g. the 
so-called psorosperms of the ureter. Intracellular, free, and sporing 
forms can easily be recognised. They are present in the most varied 
kinds of sarcoma. Thus I have found them in Myeloid sarcomas of 
bone, both endosteal and periosteal, alveolar sarcoma of skin, lympho- 
sarcoma of the mediastinum, round-celled sarcoma of the testis, and 
others. The number of these bodies present has hitherto been pro- 
portionale with the rapidity of growth. In only one sarcoma, an 
alveolar growth of the thigh removed by Mr. A. T. Norton, have I 
failed to recognise all the stages described above. And in this case 
the earlier intracellular phases were distinctly represented. 
I venture to publish this brief and imperfect note in the hope 
that it may lead other pathologists to investigate the matter. 
London, 26. Sept. 1894. 
1) Jackson Clarke, Morbid growths and Sporozoa. fig. 31, 5 and 6. 
