156 Proceedings of the Royal Irish Academy. 



substance; but this is only conjectural. (PI. 14.) In Jo?;A Cienkowski's 

 and the present form the tracks give off branches, and incorporate 

 with others which they cross, admitting of the spindles taking very 

 circuitous routes. 



In Cienkowski's forms he mentions that the tracks (rigid as they 

 seem at first) hy-and-hy take on " a mucous consistence, more or less 

 enveloping the spindles," and they form "knot-like expansions, in which 

 vacuoles occur;" but notwithstanding these facts, the author regards 

 the tracks in such condition as only ' ' most deceptively presenting the 

 appearance of a protoplasm-plate ;" does not this seem somewhat con- 

 tradictory ? In our form the tracks seem to be given off from the 

 central mass (pseudopodium-fashion), and can be wholly or partially 

 retracted. 



Cienkowski denies to the spindles any power of motion except in 

 connection with the trades, but in both of his and in the present form 

 'these have the power spontaneously to leave the general crowd inside 

 the central mass, at first without apparent contact with a track, then, 

 propria motu, to mount the one along which it is to make its journey. 



But, further, in connection with a fungal, the identity of which 

 was unknown to the author himseK, Cienkowski had previously drawn 

 attention to a filamentary form of plasmodium, with " spindles" mov- 

 ing along the threads.* This he describes thus (curtailed): — "Upon 

 culture of these for some time upon a slide, I found the entii'e field 

 covered over by a branched network of threads, which here and there 

 showed fusiform thickenings. Upon following the coiu'se of these 

 threads for certain distances, large differently-shaped colourless proto- 

 plasma-masses were encountered, from which the whole structure 

 di'cw its material as from a reservoir — so to say, budded out from it. 

 Upon attentive examination of the plasma-aggregates, it rendered 

 itself apparent that, at any place thereof, a projection or promiaence 

 first makes its appearance. This prominence becomes constricted at 

 its base, assumes a fusiform figujre, then, removed from the principal 

 mass, drawing a thread with it. In the same way sprouts out from 

 tlie protoplasm a new spindle, which likewise thins off at its base into 

 a thread, and follows the one fii'st formed. Whilst thus continuously 

 new spindles and threads proceed from the main reservoir, and become 

 carried along the ■'track' (' Fadenbahn'), the whole thread creeps 

 forwards, the end spindle directed foremost. The filaments proceeding 

 from the reservoir are to be identified with the basic substance of the 

 Plasmodium, the spindles and strings with the granular substance. 

 The movement of the thread is extremely slow, scarcely dii'ectly per- 

 ceptible, that of the spindle much more noticeable. 



" Ml route the spindles may not be equally mutually remote ; here 

 and there one becomes accelerated, and lays itself longitudinally on 

 the one preceding it ; this is followed by another, and so on. In this 



* Cienko^yski ; "Das Plasmodium," in Pringsheim's "Jahrbucher fiir wiss. 

 Bot." Bd. iii., p. 408. 



