“206 MEMORANDA. 
in the water wherein the part had been broken by pressure 
and friction between the glass object-plate and cover. The 
raphides in the green cotyledons were somewhat smaller and 
less plentiful than in the plumule and fully developed stem 
and leaves. 
The difference in question between Onagraceze and their 
nearest allies of other orders is not only very curious, but is 
one of those numerous phenomena which remind us of how 
little we know of the recondite operations of vegetation. 
Take, for example, two plants, as Kpilobium hirsutum and 
Lythrum salicaria, similar in habit and growing closely 
together in the same soil of the river-bank, and observe the 
signal difference of their products—the one plant, as a 
regular part of its healthy structure, abounding during its 
whole existence in raphides, the other as regularly destitute 
of them, and affording sphzeraphides instead, differing as 
much in form as they probably do in chemical composition 
from raphides. Supposing, then, as there is some reason to 
‘do, these crystals respectively are phosphate and oxalate or 
some other salt of lime, a leading and constant function 
of the Onagracez would be the formation of the phosphate, 
while the Lythracez would be a laboratory of a different 
salt—the performance of each of these diverse operations 
being a regular and special design of the plant-life in such 
cases. 
But though we know so little of this subject that its sig- 
nificance remains a mystery to us, we may now make good 
use of the facts already revealed as botanical characters, pro- 
vided we distinguish truly, as proposed in the last number 
of the ‘ Annals,’* raphides from sphzeraphides, so as not to 
confound such different things under one and the same 
term, taking care also to observe how far the spheraphid 
tissue (of which an engraving} was given in the same number 
of the ‘ Annals’) may be characteristic of certain orders. If 
we confine the word raphides to the needle-like crystals 
commonly occurring in bundles, it may be the expression of 
a more universal diagnosis between such orders as Ona- 
* Without some such definition as therein proposed be used, there will 
be, as there has long been, great confusion. It is merely perplexing to say 
that such a plant, or order of plants, affords raphides, unless it be defined 
what is meant by this term. It should be confined, as I have lately confined 
it, to the acicular forms occurring so commonly in bundles; and all the eon- 
glomerate forms provisionally, should be called spheraphides. These last are 
much more common and widely diffused than true raphides.—G, G, 
+ The outlines of the crystals are often more or less rounded or granular, 
not so sharp and distinct as there represented. In that number of the 
“Annals,” p. 228, for Cucurbitacee, read Dioscoreacee. 
