406 Prof. G. Gulliver on Raphides and other Crystals, 



XXXIX. — Observations on Raphides and other Crystals. 

 By George Gulliver, F.R.S. 



[Continued from p. 295,] 

 Crassulacece, Ficoidece, and Cactacea. — In former examinations 

 of a few of these plants, raphides were always found in Ficoideae, 

 and never in Crassulacese and Cactacese. Of these three orders 

 parts (leaves when not otherwise noted) of different species have 

 since been obtained, chiefly through the kindness of Mr. J. 

 De Carle Sowerby, Mr. W. H. Baxter, and Mr. Cox, of which 

 the examinations will now be given. Crassula tetragona : a few 

 oblong-cubic or prismatic crystals in liber or alburnum of stem. 

 C. {perfossa ?) : a few short, abruptly truncated prisms. Bryo- 

 phyllum calycinum : some sphseraphides and detached minute 

 square crystals. Monanthes polyphijUa (stem and leaf), Sedum 

 populifolium (woody stem and leaf-buds), S. dentatum, S. 

 kamskatkicum (root and leaf-buds), Sempervivum rubricaule, S. 

 arachnoideum, S. anomalum, S. hirtum, Echeveria secunda, E. 

 pumila, E. papillosa, E. bracteosa, Pachyphytum bracteosum, Co- 

 tyledon ? arborescens, C. umbilicus, Rochea falcata, and Tillaa 

 muscosa : no raphides, and other crystals very scanty. Cereus 

 hexagonus, C. jiagelliformis, Rhipsalis paradoxa, protuberances 

 and spines of seven species of Mammillaria, four species of 

 Epiphyllum, and two of Opuntia were also all devoid of raphides. 

 But in E. speciosum were numerous coarse sphseraphides, a sort 

 of crystalline grit, from which abruptly truncated prisms ra- 

 diated; and 0. nigi'icans and fruit of 0. vulgaris were thickly 

 studded with sphseraphides, about -g-l-oth of an inch in diameter, 

 especially in the outer part of the rind ; while in its inner part 

 and parenchyma the sphseraphides were less numerous, more 

 irregular in size, and so much larger that their mean diameter 

 was not less than T-o-o^h of an inch. Of the fifteen species re- 

 ceived of Mesembryanthemum, every one abounded in raphides, 

 commonly in bundles ; and many larger crystal prisms were 

 seen in these plants : the raphis-cells were generally of a short 

 oval form, by no means so elongated as in many other orders, 

 and in the centre frequently appeared black from the accu- 

 mulation of raphides. This was well seen in the leaves of M. 

 vaginatum, M. densum, and M. caninum, and also in the paren- 

 chyma and pith of the stems of M. barbatum, M. [tortuosum ?), 

 and M. perfoliatum. 



In Prof. Balfour's 'Manual of Botany,' these orders stand 

 thus : — 90, Crassulacese. 91, Ficoidese. 92, Cactacese. And now 

 all the above observations show raphides constantly present in 

 the section Mesembryese of the central order, and as constantly 

 absent in the two other orders. Still, that this remarkable 



