1S6 
ORIGINAL COMMUNICATIONS. 
have previously entered our protest against admitting new 
species founded upon such slender evidence, and the reason 
alleged in palliation of this procedure in the present instance 
cannot be upheld without detriment to Science, in as much as 
what is positively ascertained would be rendered obscure and 
complicated. They assert that this species should be sepa- 
rated, if solely for the purpose of attracting the attention of 
Naturalists to it. Undoubtedly the fact of the existence of 
differences in the character of the plants which enter into the 
commercial article should be pointed out and minutely noted, 
but the liberty of adding a new species to those already known 
must be based upon more certain materials than the broken 
fragments making up the aggregate of a bale of Senna. The 
general principles of varieties, already alluded to, will afford 
a clue to the explanation of the statements which they make. 
According to their account the species *' is composed of small 
folioles exactly oval, acute at the summit, lightly pubescent 
below, at least in the vicinity of the midrib; they are fragile, 
of a pale green, and most frequently broken, the folliculi are 
thin, pale yellow, a third smaller than those of the preceding 
species, and not curved as they are; they contain some cordi- 
form whitish seeds, with little trace (prominence) of them in 
the middle of the pods." It is to be remarked that these are 
found in the Senna from Tripoli, well known as an inferior 
article, composed for the most part of the Cassia with acute 
leaves, and from the description, it is apparent that the por- 
tions of the specimens alluded to are in an immature state; so 
that the question might be settled from these circumstances 
without further comment. But they state that there is a simi- 
larity between the plant thus distinguished, and the figure of 
C. lanceolata given by Colladon, which is confirmative of 
the view we have taken, and evinces that this author was un- 
fortunate in the selection of his specimen, not that he was 
mistaken in his plant. The dissimilarity of the figures of 
Delile and Nectoux has been noticed, and the same general 
remarks apply here, as also the great variety in the shape and 
size of the leaves and pods of the genuine Alexandrian Senna. 
