114 WwW. ARCHER. 
interruption, no very perceptible change of figure from the 
spindle-form is usually seen, except the flat side occasionally, 
or the furcate form more rarely, both as before adverted to. 
In the case of two flattened spindles, they may sometimes be 
seen gliding at opposite sides of the filament, and one may pass 
the other with the filament between, and now without any 
change of figure, unlike what occurs when two or several 
meet at the same side and cluster together. 
Not less curious is it again, seemingly, how these little 
bodies remain upon the filament. What power keeps them 
there? ‘They never seem to glide off or to be met with in 
the water around. In fact, these little performers on the 
“slack rope”? seem to hold on admirably—but then their 
action is very deliberate ! 
I have sometimes supposed that, surrounding Joth spindles 
and filaments, a very subtle and delicate sheath, or envelope, 
must exist, of some amount of contractile power, whose action 
might exercise a propelling force to urge the spindles along 
the median axis, or, at least, to act as an auxiliary in con- 
junction with their inherent contractile locomotive power. 
Under a very high amplification indeed I have thought to 
haye seen such a delicate envelope, but I cannot say that the 
appearance might not have been due to an optical illusion. 
However, such a structure would not be without parallel 
in certain Helizoan Rhizopoda, for instance, Actinospherium 
Eichhornii, in which the radiating pseudopodia possess a 
central axis of firmer consistence (surely not comparable to a 
spicule), covered by a softer sarcode envelope, certain 
granules passing between, evidently carried passively by the 
latter. But the movement of the spindles, consisting, as it 
does, of a quiet and smooth glide, is of different character. 
The axis of the pseudopodium of Actinospherium, compara- 
tively speaking, is a much coarser object than the delicate 
filament upon which the spindles travel in the present organ- 
ism, and the soft involving granular sarcode of the former 
is indeed a very palpable thing as compared with the very 
subtle sheath assumed to possibly exist in the latter. : 
There exists a certain minute rhizopod, of which I have seen 
but very few examples, and have therefore had by far too 
restricted opportunity to study it to give an account of or to 
describe it. J¢ ts there, however, and even, as is probable, I 
may not myself be so fortunate as to re-encounter it, it will 
most likely be found by other observers, and far better treated 
of. For the present purpose it is enough to mention that 
this form is of an orange or buff colour, globose its “ normal ” 
figure, but is capable of much alteration of outline, and it is 
