DEVELOPMENT OF PARASITE OF ORIENTAL SORE. 751 
lum is one and a half times or twice the length of the body 
of the parasite, and has from six to eight symmetrical undula- 
tions. In life the flagellum is very active, and moves very 
rapidly with a lashing, wave-like, not a corkscrew-like move- 
ment ; i appearance it strongly resembles a spirochete. 
The parasites are frequently found in pairs (fig. 6, f-7) 
[doubtless indicating fission]. Sometimes a pair consists of 
a thinner and a thicker individual [compare the splitting off 
of spirillar forms in L. donovani, described by Leishman 
and Statham, ‘Journ. R.A.M.C.,’ iv, 1905, p. 321]. 
[The foregoing account contains the pith of Dr. Row’s first 
letter to me, and appears to represent the normal healthy 
development of the parasite in cultures. With the object of 
obtaining a slower development of the parasite, especially of 
the stages previous to the formation of the flagellum, material 
was taken from a case of longer standing, and the parasites 
were allowed to ‘‘ stew in their own juice” for three days in 
a sealed tube at laboratory temperature before cultivating 
them. The result was a slower development of the parasites 
in the cultures, with production of peculiar forms probably 
representing abnormal or degenerative forms of the parasites 
weakened by the unfavourable conditions of its development. 
An account of these cultures forms the substance of Dr. 
Row’s second communication to me, and a brief abstract of it 
follows.—E. A. M.] 
The parasite, when derived from an old case (in which the 
lesion is about to break down into pus and is on the point of 
ulcerating, and when, consequently, the contents of the 
lesion are rich in leucocytes and pus), gives rise in cultures 
to a slow and irregular development, both in numbers and 
in morphological characters. Under these unfavourable 
developmental conditions very few typical well-developed 
and mature flagellates are produced ; the products of stunted 
forms either do not reach the flagellate stage at all, or, if 
they do so, they are unable to continue their existence long. 
The following seems to be the general plan of the develop- 
ment. The parasites begin to elongate into ovoids (fig. 7, a) 
