30 



It is difficult to condense his long and interesting account so 

 as to do fair justice to the matter, but the foregoing may, I 

 trust, convey an epitome of his principal observations. 



I myself would argue as Greef does in one place that in 

 Acanthocystis turfacea, just as little as in A. Pertyana, is 

 there anything around the central sarcode body which might be 

 denominated a special membrane. The so-called " lorica" — 

 " biegsamer Panzer" — " verdichtete Rindenschicht" — can be 

 but the expression of the mutually approximated discoid 

 bases of the radial spines being held together with a con- 

 siderable amount of coherence by means of some intervening 

 bond not readily perceptible. One meets not unfrequently 

 portions of the periphery of a defunct Acanthocystis, per- 

 haps as much as a fourth or fifth of a circle (nay, whole 

 globes sometimes), all the sarcode clean gone and nothing but 

 a greater or less number of radial spines left, and those still 

 cohering by their discoid bases, the shafts radiating in the 

 same manner;, just as they would if they stood at the peri- 

 phery of a still living example. See also Greef's fig. 15 of 

 an " encysted" state of this form, where the peripheral system 

 of spines, still mutually coherent, stand off a distance from 

 the contracted inner sarcode body, the latter now surrounded 

 by its special investments. But Greef's views expressed in 

 his account of this outer boundary (page 488) , do not seem to 

 me to coincide with those previously expressed (page 484). 

 The following extract gives the ipsissima verba used by Greef 

 in the latter place referred to : — " Ich meinerseits habe 

 keine bestimmte Anzeichen finden konnen, die mit Sicher- 

 hejt eine besonders abgegreuzte und erhartete Rindenschicht, 

 oder was doch wohl dasselbe sagen will, eine INIembran 

 bekunden, wohl aber mehrere die auf die Abwesenheit einer 

 solchen schliessen lassen." And he adduces as evidence of 

 the foregoing view the fact (not unfrequently to be seen), 

 that large finger-like sarcode projections are capable of being- 

 extruded through the outer boundary, these withdrawn, and 

 the place of their exit effaced, and the spines again all nor- 

 mally in situ. He also refers as additional evidence to the 

 extrusion of green granules by a separation of the spines, 

 and by intervening opening which again disappears. All this 

 is just and according to fact, but I think the foregoing extract 

 does not seem to accord with the following, in alluding, in 

 the encysted state (fig. 15), to the very same outAvard boun- 

 dary where the bases of the spines touch and form a hollow 

 globe, now standing off leaving a vacant margin around the en- 

 cysted body : — " Die Oberfiache dieses Saumes wird viehnehr 

 durch cine zarte und srlashelle aber starre und undurcluh-ing- 



