152 SELECTED NOTES FROM 



defined than I had ever yet seen. This would lead to the 

 inference that time was not so much necessary to their formation, 

 but rather that their development depends mainly on the size of 

 the metallic particles forming their nucleus. 



A. Allen. 



BOTANICAL. 



Crystals in Leaflet of Lathyrus hirsutus. — Professor Gulliver 

 points out that the leaves and other parts of most of the Legu- 

 mi?ioscB contain crystals. In some plants they are more abundant 

 than in others, but in few do they appear to be more plentiful than 

 in this, one of the rarest of our British species. Crystals gene- 

 rally require the Polariscope to show them properly. 



For some time, all plant-crystals were confused under the 

 common name of Raphides, but Professor Gulliver has now 

 divided them into four principal classes : — 



ist. — True Raphides, which are acicular or needle-shaped in 

 form, and with a rounded shaft, vanishing at both ends to a point. 

 Their general shape is so like a needle, that they have been 

 named after that useful article, from the Greek pa(pLs, a needle. 

 They occur loosely in bundles, each bundle often containing some 

 hundreds, and commonly within a cell. 



2nd. — Long Crystal Prisms, which have distinctly angular 

 sides, and truncate or pointed ends ; they are always twice, or 

 more, as long as broad. Sometimes they are as long and thin as 

 true Raphides, but may always be distinguished by their angles. 

 They are found either singly, or two or three together — so con- 

 solidated that they never admit of niotion on each other. 



3rd. — Short Prismatic Crystals, of cuboid, lozenge-shaped, 

 square, and other forms, more or less prismatic, innumerable, and 

 contained in cells firmly impacted in the tissues ; mostly in chains 

 along the vascular bundles of the plant ; they are not quite as long 

 as broad. 



4th. — Sphcer aphides. These are globular, conglomerate masses 

 of Crystals, with their projecting ends either sharp-pointed, or 

 rounded. Those of the latter form are sometimes attached to the 

 cell-wall by a pedicel, and resemble in form a blackberry. The 

 Crystals are often granular, smoothish, or stellate on their surface, 

 and are commonly dispersed throughout the leaves and some other 

 parts of the plant. 



Of these four classes, the third (Short Prismatic Crystals) 



