GKAF ZU SOLMS-LAUBACH — MONOGRAPH OF THE ACETABULAlilE.E. 15 



sufficient to demonstrate it. The thick middle layer is bounded on the inside by a relatively 

 thin, stratified, strongly refractive layer, turned blue with chloriodidc of zinc ; it directly 

 encloses the contents. Outside the layer bearing the incrustation is the thin cuticle-like 

 membrane, either not stained with preparations of iodine or merely turned yellow ; 

 at the commencement of swelling it readily rises up in folds and is then easily 

 observable. 



If the section passes through the lid of the spore (Plate IV. fig. 8), several complications 

 will be found at its margin. The marginal surface between lid and spore-membrane 

 appears on both sides as a sharp line running through the membrane. This line consists 

 of an extremely delicate, perpendicular lamella passing outwards into the cuticuloid layer 

 and inwards into the internal layer. That these connections exist and that the lamella 

 goes transversely through the incrusted layer is shown particularly clearly at the com- 

 mencement of the swelling of the section, where, for example, the cuticuloid layer rises 

 in folds and one sees the lamella in question emerge distinctly above the incrusted layer 

 and pass into the cuticuloid one. It undergoes in this apparently a stretching, not 

 shared in by the incrusted layer in the mass. We have seen that the incrusted layer 

 possesses a denser margin on its inner and outer sides ; a similar one is also presented 

 towards the transverse lamella forming the lid-margin, so that it is accompanied on both 

 sides by a more strongly refractive seam of the incrusted layer connecting the similar 

 portions of the outside and inside, in the lid as well as the rest of the spore-membrane. 



When sections passing through the lid have been carefully treated with acetic acid and 

 then stained with a little iodine, the subsequent treatment with concentrated sulphuric 

 acid causes the membrane, coloured blue, to swell up enormously. The outer cuticle- 

 like lamella and the lamella separating spore and lid do not take part in the staining. 

 The inner layer swells up and exhibits its stratification ; soon this stratification becomes 

 indistinct, and all begins to dissolve, with the exception of the outer cuticuloid layer and 

 the lamella between spore and lid. Finally this latter is destroyed, and there remains 

 only its point of connection with the outer layer as a knob-like swelling forming a circle 

 in a surface view of the section. In the end there is left over only the cuticuloid layer, 

 which undergoes no farther alteration. This layer, however, is not a true cuticle, since, 

 apart from its resistance to sulphuric acid, it sho^vs none of the characteristic reactions 

 of cuticle, is unaltered in chromic acid, and does not turn yellow on warming in potash. 

 Of what nature this modification is must be left undecided. 



In the examination of spores, decalcified most carefully with very dilute acetic acid, 

 there always appear outside the cuticuloid layer several very delicate parallel marginal 

 lines which appear to indicate the presence of a clear, stratified, gelatinous envelope. If it 

 be really present one would regard it as the equivalent of the slime mass which envelops 

 the spores of Acicularia and binds them together, serving as the substratum of calcifi- 

 cation*. Since, however, in examining sections of embedded spores, I have never been 

 able to discern again the least trace of this, I am doubtful whether these lines may not 

 be ascribed to an optical illusion. I should have liked to examine the condition of the 

 spore- membrane on the opening of the lid, but I had no suitable material. It is 



* The adhesion of the spores of Halicoryne spicata might be similarly explained. 



