122 W. ARCHER. 
the obstacle, upon a fresh start the fusiform figure is reas- 
sumed. Sometimes, says the author, a backward motion may 
take place, ‘‘ though indeed the final exit from the water 
appears to be the purpose of this curious wandering.” As 
to the cause of the movement, the author knows of no fact 
capable of leading to an explanation, being of opinion, how- 
ever, that, ‘‘owing to the rigidity of the track, the cause is to 
be sought in the spindles, though the latter, away from the 
track, have not the power to move.” 
Touching the “tracks” themselves, the author seems to 
regard them as not differing except in tenuity from the 
general hyaline basic substance. He was able, by the applica- 
tion of acetic acid, to perceive that the previously seemingly 
uniform substance now showed a very fine fibrous structure, 
and pressure on the covering-glass enabled him to detach the 
strings from the central body. When, however, the whole 
fabric becomes fully evolved under the microscope (that is, the 
whole “ tree ” or “ labyrinth ”’ developed), it seems to possess 
no contractility, evinces no movement on the surface or in 
the interior, no projection or retraction of processes or rays 
comparable to the pseudopodia of the Rhizopoda, the whole 
is now a rigid, motionless structure (except, of course, the 
wandering spindles). ‘The author would leave the question 
an open one as to ‘‘ whether the tracks represent a system 
of communicating tubes, or solid interwoven threads.” 
The principal difficulty in his arriving at a conclusion is 
due to the extreme minuteness of the threads, which scarcely 
allows of the mutual relation of these to the spindles being 
observed. The author could not satisfy himself as to whether 
the spindles executed their movement tm the threads or be- 
tween them ; as he regards the passage of a spindle, from the 
main filament to a branch, as being compatible with either 
interpretation. Also, he says the fact that, upon the appli- 
cation of iodine, the contour then seems as standing off 
from the spindles, directly continued above and below into 
the filaments, may be used in favour of either view : this con- 
tour, with its dependent threads, may be interpreted as the 
expression of a ‘‘ tube in which the spindle moves, or as that 
of two threads in contact longitudinally.” The author him- 
self leans to the latter view. 
Notwithstanding the seeming fibrous nature of the mass 
under certain circumstances, and occasional tuft-like pencils of 
short linear prolongations making themselves sometimes appa- 
rent, Cienkowski thinks there is not thereby afforded a reply 
to the query whence properly the material to form the tracks 
proceeds ; is it the basic substance of the central body which 
