DUBLIN MICROSCOPICAL CLUB. 89 



cells ; their bounding walls were rather thick, squarish in outline, 

 and rounded at the corners. Each cell contained an oblong pris- 

 matic crystal with usually distinct pyramidal extremities, nearly 

 filling it, and with its longest axis in the direction of the string ; 

 some of the crystals which were obliquely placed may have been 

 dislodged in making the section. The careful examination of the 

 crystals while in situ left no doubt as to their true nature ; it was 

 possible, moreover, with a little trouble to isolate them from their 

 containing cells. They polarised distinctly, which showed that 

 they at any rate did not belong to the cubic system. The general 

 parenchyma of the stem contained an abundance of ordinary 

 raphides, which Gulliver had also observed in the leaves and 

 "bark." "Crystal prisms" were distinguished by GruUiver from 

 raphides ; these last were absent in Allium, while in the section 

 of the genus to which the common onion belongs, prisms were 

 abundant, and consist, according to Dr. Davy, quoted by Gulliver, 

 of oxalate of lime and magnesia ('Ann. and Mag. Nat. Plist.,' 3rd 

 ser. 13, pp. 293 and 509). In IridacecB, prisms consisting of 

 oxalate of lime are very abundant (ibid., vol. 15, p. 212), while in 

 Bonapartea juncea, as in Pandanus, raphides and prisms are both 

 present (ibid., vol. 16, p. 408). Por notices of crystalline bodies 

 from the bark of several exogenous trees taken from the 'American 

 Journal of Microscopy, see ' The English Mechanic' for June 2nd, 

 1871, p. 254. 



Mr. Thiselton Dyer also called attention to the elliptical sep- 

 tate spores of a coniomycetal fungus, Podisoma juniperi, Fr. 

 These showed the commencing appearance near the septum of the 

 germinating filaments, which finally produce spores of the second 

 order, homologous, therefore, with the sterigmata and primary 

 spores borne by the sporophore of the Hymenomycetal Tremella. 



Dr. Moore showed instructive (scorched) sections from pampas 

 grass. 



Mr. Archer drew attention to some examples of Staurastrum 

 oxyacanthum (ejus), presenting the same peculiarity as that first 

 pointed out by Dr. Barker in Staurastrum gracile, which, however, 

 he (Dr. Barker) was inclined rather to regard as of specific value ; 

 that is, instead of presenting three arms in end view, being com- 

 pressed or plane, and showing, consequently, only two arms in end 

 view. Amongst the examples now exhibited some presented them- 

 selves with two arms only at each end or segment ; some with two 

 on one segment and three on the other; some with two on one 

 segment and four on the other ; and some with three on one seg- 

 ment and four on the other — all side by side. This departure 

 from the typical form, especially the plane or compressed, was, 

 however, much more scanty than Dr. Barker's plane or compressed 

 form of St. gracile in the bogs in Co. Westmeath (near Mullingar), 

 where the latter is the prevalent form, and,'indeed, not rare, whilst 

 the ordinary form in other places is so ; but in ^S*^. oxyacanthum, 

 not at all a rare species, the present is the first instance in which 

 this departure from the ordinary form, that is, being compressed, 



