258 DR. DUFFIN, ON PROTOPLASM. 
of the smaller alveoli. Schultze,"in his attempts to trace 
these radicles more accurately, encountered a number of cell-, 
like bodies in the cortex of the nucleus. These were particu- 
larly distinct if the animal had been killed by a temperature 
of 42°C. A high power, then, shows that these bodies le 
scattered in the cortex of the darker medullary substance. 
Their number may amount to forty and upwards. They are 
globular formations, with very delicate walls, and with coagu- 
lable, albuminous contents, and usually with numerous small, 
apparently homogeneous nuclei. They are in no way con- 
nected with the roots of the pseudopodia. 
Such being the chief characters presented by the pseudo- 
podia of the Rhizopods, Schultze compared them with the 
phenomena of motion that are to be observed in vegetable 
protoplasm, thus carrying out the idea of Unger, which has 
been already alluded to. The objects which admit of the 
most direct comparison with the pseudopodia of the Polytha- 
lamize are the threads of protoplasm that traverse the cell- 
cavity of Tradescantia, Viola, Cucurbita, and Hydrocaris 
leaf-cells. Several filaments of varying thickness pass from 
various parts of the protoplasm, and particularly from that 
portion which surrounds the nucleus, across the cell in dif- 
ferent directions. They consist clearly of a basic substance, 
containing highly refracting granules. These latter run in 
the interior, or as on the surface of the filaments, either only 
in one direction, or in both, on one and the same thread. 
On the broadest filaments this double direction of the stream 
is almost constantly seen, and it may even be noticed in 
threads that are only just perceptible. When granules meet 
they may either pass each other, or the one may carry the 
other off—a proof that two separate filaments do not consti- 
tute the cause of the double direction of the stream. On the 
same thread a rapidly moving granule may overtake its more 
sluggish neighbour. The threads often bifurcate, and when 
a granule reaches the point of division, it may oscillate before 
selecting its further course. The shape and direction of the 
filaments are liable to constant change. 
Bridges are formed and run upwards or downwards be- 
tween the fibres, shorten as the latter approach, vanish as they 
coalesce, till a broad stream flows where previously there had 
been only separate filaments. Occasionally longer spindle- 
shaped masses pass along, with the same or a somewhat 
diminised velocity as the granules. The results obtained by 
the influence of various reagents (as distilled water, dilute 
acids and alkalies, the electric current, &c.) have so close an 
affinity to those obtained with the pseudopodia as to amount 
