314 Phillips on a Comparative Study of the 
ence of relation between the two movements.” Zukal (98) 
also regarded the motion of Spirulina as intimately asso- 
ciated with growth of the organism, and as comparable to 
the growth of a tendril. 
Palmer (61) has observed in Eunotia major, proto- 
plasmic processes at the corners of the frustules, which he 
called “coleopodia,” which were connected with a thin layer 
of protoplasm or “coleoderm” surrounding the whole dia- 
tom. He said: “The above results of observations and ex- 
periments would seem to be conclusive proof that E. major 
and by inference other nearly related species and genera of 
the Fragillariee move by the action of organs that may be 
called coleopodia. This conclusion, however, is far from 
touching the question of the means of locomotion in Pinnu- 
laria and its allies. It may be added, in this connection, 
that while a large Pimnularia in rapid motion not infre- 
quently gives evidence of brisk internal currents, such as 
Muller (56) has described, such currents have not been 
observed by me in Eunotia. Under rather high powers one 
only sees, near the corners of the frustules, in the vicinity 
of the raphe, a certain internal commotion among the very 
small protoplasmic granules, a spasmodic movement back 
and forth, a waving about. This movement differs alike 
from the streaming of cyclosis and the Brownian trembling, 
and it is traceable with difficulty, if at all, far from the cor- 
ners. Nevertheless, the channelling of the frustules is of a 
character to indicate the existence of currents, and further 
observations may yet reveal them.” 
Barkas (2), in speaking of the movement of Bacillaria 
cursoria, observed that “the small, gritty particles on the 
sides of the frustules moved freely backwards and forwards, 
in a hurried manner along the edge of the frustules, as 
though they were occasionally driven by cilia, or as if they 
had automatic or voluntary motion. I observed that they 
moved when the diatom remained stationary.” 
It seems to me that the osmotic theory can hardly account 
