NEW TYPE OF PPvOTISTAN PARASITE. 
451 
was Certes^ opiuion originally. From a further study of 
Seleiiomastix, however, we feel at present very doubtful 
whether it is a true flagellate. Supposing for the moment 
that it is, the question of the orientation of the body is a very 
important one, because this determines, of course, the nature 
of the division. We have not the slightest indication that 
the middle of the concave side — approximately the point of 
insertion of the flagellum — represents the anterior end; on 
the contrary, such evidence of antero-posteidor polarity as we 
have obtained points to this being in the direction of the 
longer axis of the body, both in the crescents and the ovals. 
Hence we must regard the division as transverse. Apart 
from the entire order of the Dinoflagellates, there are scarcely 
any Flagellates in which division is transverse. We can find 
no hint whatever of Dinoflagellate characters in Seleno- 
mastix. In a crescent which is not commencing to divide, 
there is neither a second flagellum nor any sign of an annular, 
transverse groove. It is equally difficult to see any indication 
of relationship among the Euflagellates. For one thing, the 
peculiar scattered or diffuse condition of the chromatinic 
substance is very different from the definite nucleus which 
is typical of flagellates. Another point which in our view 
weighs very much against the flagellate affinity of this new 
creature is the conviction we have that it is capable (either in 
the crescent or the oval phase) of moving by means of its 
body alone, somehow, independently of the flagellum, when 
this is present. We have next to search, therefore, among 
the vast assemblage of organisms collectively known as 
bacteria for a clue to the relationships of Selenom astix.^ 
^ So far as the ovals alone were concerned, we did not overlook their 
possible connection with some of the Saccharoinycetes, such as S c h i z o - 
saccharomyces. Thanks to the kindness of Dr. Harden, of the Lister 
Institute, we have been able to compare the ovals with organisms of 
this group, and it was at once apparent that with them they have nothing 
whatever to do. Further, the ovals do not resemble in any way another 
yeast-like type of organism, namely Blastocystis, which has been 
lately described. 
VOL. 59, PAET 3. — NEW SKKIES. 29 § 
