456 
H. M. WOODCOCK AND G. LAPAGE. 
(4) We suggest that the second type of oval gives rise to 
the first type, and also that the crescent may pass into the 
first type of oval hy the loss of the flagellum. We have no 
indication wliether the crescents may be developed from the 
ovals or not. 
(5) Apparently the only Flagellates from whicli this orga- 
nism could be derived are the Dinoflagelhites, and, apart from 
the transverse division, there is no indication of any aflinity 
with this group. Further, the nature of the ^Aiucleus and 
the capacity of moving by the body alone make it very 
doubtful if this parasite is a true protozoan. 
(6) Selenomastix ruminantium differs in important 
respects from any known bacteria. It has no affinities with 
Schizo-saccharomycetes, with Blastocy stis, nor with the 
Spirocheetes. In certain characters it shows a resemblance 
to one or two large Spirillar forms, or to certain members of 
the Sulphur-Bacteria (e.g. Ophidomonas), but while its 
derivation is possibly to be sought in this direction, it is, 
nevertheless, very far removed from such forms. We may 
have in Selenomastix an example of a Pro-flagellate. 
EXPLANATION OF PLATES 29 and 30, 
Illustrating the paper by Dr. H. M. Woodcock and Mr. G. 
Lapage, On a Remarkable New Type of Protistan 
Parasite.^’ 
[All the figures are magnified 2000 times linear. We are indebted 
to Miss Rhodes for kindly drawing a few of them.] 
Figs. 1-38. — All the figures are of crescents, and are from “ wet- 
fixed ” films, stained by iron-haematoxylin. 
Figs. 1-19. — Single individuals, of various size, showing different 
conditions of the envelope and of the chromatinic substance. 
Figs. 20-26. — Dividing individuals possessing two flagella, but in 
which the body does not yet show indications of fission. In figs. 20 and 
23 the actual splitting of the flagellum is shown. 
Figs. 27, 28, and 31. — Later stages of fission, in which the body is also 
dividing. 
