72 
Mr. G. Scott adverted to the comparative untrustworthiness of 
anemometers, and suggested the possibility of the indicators going 
further than they should. Should not the instrument be stopped at 
given intervals—say every half-an-hour? The returns, he thought, 
were much more likely to be accurate if this were done. . 
Mr. SAWYER admitted that different sized instruments gave 
different returns. 
Mr. W. H. NASH was of opinion that Osler’s was a much more 
accurate instrument than Robinson’s. 
APRIL 23RD. 
MICROSCOPICAL MEETING.—MR. WONFOR ON 
“PLANT CRYSTALS.” 
In most of the manuals on Botany or the Microscope, certain 
crystalline bodies found within the cells of plants were designated by 
the name Raphides,/or needle-shaped bodies, a term inapplicable to 
some, because they were not needle-shaped, and on the whole mis- 
leading, because in the lists of plants generally given as containing 
them, it would seem as though their appearance was an accidental 
circumstance in the economy of the plant, instead of a constant 
quantity, not confined to one period of the plant's growth, but found 
in all stages of its existence. 
The first to reduce to something like order and to indicate the 
value of Plant Crystals, in determining the differences between plants 
of otherwise closely allied families, was Professor G. Gulliver, by 
whom they had been arranged into the three STOUPS eRe 
Sphaeraphides, and Crystal Prisms. 
Raphides were transparent colourless crystals, needle-shaped, 
and tapering to.a fine point at each end, loosely connected in bundles 
of twenty or more in oval or oblong cells of slightly larger dimensions 
than themselves. The slightest pressure on the tissues of a portion of 
a plant, when under examination, causes them to escape from their 
cells. Examples could easily be obtained either by making thin 
sections or simply tearing with needles a portion of the tissues of any 
member of the balsams, woodruffs, evening primrose, arum, orchis, 
and some of the iris family 
