Observations on British Zoophytes and Protozoa, 155 



commence, and become constantly more numerous. The 

 branches, after issuing or becoming free, easily reach their 

 neighbouring filaments, apply themselves to these, and then 

 appear as anastomoses. By the multiplication of such ap- 

 parent anastomoses those reticulated figures are produced 

 which are known under the name of the Sarcode net. At 

 the same time bridge-like unions, and membrane-like struc- 

 tures, between the filaments become visible." ''Favourable 

 conditions for the multiplicity of forms, and for their ready 

 and often imperceptible change, are also furnished by the 

 extraordinary number of the filaments and their flexibility." 

 And he further states, that " the appearance produced by 

 these readily moveable parts in the protean system of fila- 

 ments, as if a moveable substance assumed any form or 

 spread and poured itself into any shape, is an illusion which 

 is set up especially by the circumstance that individual 

 minute parts, which are readily displaceable throughout, 

 can never be distinguished at their points of contact." 



No doubt the theory of Eeichert is exceedingly ingenious 

 and plausible, but it appears to me to be especially open to 

 two objections. 1st, If the infinitely fine fibres of Eeichert 

 had such an amount of cohesion as to enable them to form 

 bundles and membranes of apparently homogeneous struc- 

 ture, such an amount of cohesion would prevent the rapid 

 motion of the fibres on each other in opposite directions. 

 2c%, We see the same fibrous arrangement of the protoplasm 

 in the interior of the vegetable and animal cell. In the 

 cell of Anacharis, for instance, when the circulation has been 

 arrested, we frequently observe the protoplasm distributed 

 as a more or less perfect mesh-work over the whole cell. 

 After a time of rest, movements commence in the threads in 

 no respect differing from those of the pseudopodia of the 

 rhizopod, and the protoplasm creeps to the borders of the 

 cell where the circulation commences. So in the cells of 

 i lie tentacles of Coryne, the protoplasm assumes a similar 

 thread-like and reticulated arrangement ; in fact, that each 

 cell contains an imprisoned rhizopod. Perhaps the Society 

 may remember that I sometime ago showed a true rhizopodic 

 structure to exist in the pigment corpuscle of the fish, which 



vol. nr. x 



