166 NATURAL HISTORY SOCIETY OF DUBLIN. 



state : the contents of certain cells became detached from the cell- wall 

 and collected into one or more ovoid masses, which sometimes became 

 segmented; their colour became temporarily changed to a reddish or 

 reddish-brown, presently they lost colour, except a few reddish granules, 

 as in Volvox, and became essentially amoeboid, travelling up and down 

 the cells. Shortly they withdrew the pseudopodal processes, and became 

 rounded and ciliated all over, beyond which Dr. Hicks' interesting ob- 

 servations were not extended. To these cases Dr. Hicks adds another, 

 that of the amoeboid transformation of the " gonidia" of a moss. The 

 "primordial utricle" or outer protoplasmic layer became enlarged, at 

 first feebly sending out short and rounded lobose processes. Afterwards 

 the green contents vanished, and the whole body became colourless, 

 containing a few reddish-brown granules and same vacuoles ; the pro- 

 cesses became more elongate, and finally quite amoeboid, moving freely 

 about. 



To the foregoing may be doubtless added the case referred to by 

 Hofmeister,* in giving an account of the structure of the " spore-mother- 

 cell" of a particular moss, of which he writes : — " The cell- contents, 

 which are plainly surrounded by a thin layer of soft matter, very like a 

 delicate membrane, swell slightly, or not at all ; they (the cell- contents) 

 lie freely in the inner cavity of the cell, in the form of a closed vesicle, 

 surrounded by watery fluid. Individual points of the primordial utricle 

 sometimes exhibit slow expansions and retractions, similar to those of 

 the inferior animals ; for instance, the smaller Amoebae" .... This 

 is most probably a case in point, although the cell-contents, still enclosed 

 within the parent-membrane, in the instance thus recorded, were not at 

 liberty to move. 



The only other published record of what truly seems an actual case 

 in point, which I have met with, of a locomotive power due to an amce- 

 boidmotile contractility in an undoubtedveget&ble cell, is that by Schenk.f 

 This author describes the nucleated colourless uni ciliated zoospores of 

 Rhizidium intestinum (a plant destitute of chlorophyll), as capable, during 

 certain intervals, of moving about by the protrusion of amoeboid processes, 

 each thus generally presenting a constantly changing two, three, four, 

 or five-lobed figure, the lobes projecting in various directions, or for a 

 time without lobes, and drawn out and very slender, whilst the internal 

 movement of the granules was exactly that of an Amoeba. After some 

 alternations of a still and a slowly contractile condition, and of an active 

 movement by aid of the cilium with which each is provided, the zoo- 

 spore finally assumes an elliptic figure, comes to rest, loses the cilium, 

 and developes {more suo) into a new young Rhizidium plant. 



Carter too speaks of a condition apparently ' ' rhizopodous " of the 

 contents of the cells of Spirogyra crassa\\ but he has lately seen fit to 



* Hofmeister " On the Germination, Development, and Fructification of the Higher 

 Cryptogamia" (Ray Society's Publication for 1862), pp. 162-3. 



f "Ueberdas Vorkommen contractiler Zellen im Pflanzenreiche." Wurzburg, 1858. 

 X "Annals of Nat. Hist.," 2nd Ser., vol. xix., p. 259. 



