280 I'BOF. ALl.MAN" ON TIEE HKCENT EESEAECnES 



pansiou, wliieh in its ultimate ramitioatious eousists of filaments 

 of extreme tenuity. On this complicated plexus may be noticed 

 in constant motion peculiar spindle-shaped bodies Avhich, in L. 

 vifeJJi/ia, are of au orange-red coloiu', and which glide in all di- 

 rections along the course of the filaments. 



The central mass consists of a multitude of little sarcx)de 

 spherules, the whole being held together by a soft, finely gra- 

 nular substance, whicli at the periphery forms a thin enveloping 

 layer. Small aggregates of a similar sarcode occur also on 

 various parts of the filamentary network, where, however, they 

 are not held together by a cortical layer, as in the gi'eat central 

 mass. From these smaller aggregates there also run in various 

 directions branching and anastomosing filaments, along which 

 the orange-red spindles glide. 



Cienkowski has shown the identity of the moving spindles 

 with the spherules of the central mass. He has seen these 

 spherules become fusiform at the periphery of this mass and 

 then leave it in order to wander along the course of the filaments. 

 After several hours it will be seen that the greater part of 

 the spherules have assumed the spindle shape, and, abandoning 

 the central sarcode, have entered the filaments and wandered to 

 the margin of the plexus. 



The spindles are little masses of protoplasm destitute of a 

 membrane and very mutable in form. Each encloses a nucleus 

 with nucleolus, and multiplies by division. They are therefore true 

 membraneless cells. They exhibit no motion, except in the paths 

 formed for them by the branching filaments. 



Cienkowski describes the filamentary tracts along which the 

 spindles wander as destitute of contractility, showing no motion, 

 and never projecting pseudopodia. He regards the whole plexus 

 as a rigid non-mobile structure, and believes that its component 

 filaments never become fused together, but only touch one ano- 

 ther and adhei'e. He has, moreover, followed its formation, and 

 from a piece of the central protoplasm showing at first no trace 

 of the filaments, he has seen a complicated plexus developed in 

 the course of a few hours. He regards it as a gelatino-fibrous 

 excretion of the spindles. 



If this be a correct view of the nature of the plexus, it is 

 obvious that the cause of the motion is to be sought for in the 

 spindles themselves, and not in the paths over which they wander. 

 This, however, is scarcely in accordance with tlie known pheuo- 



