: ‘Pieces, but, on account of this very thickness, a good piece may be 
Vol. 1. No. 2.] BULLETIN OF THE TORREY BoTANICAL CLUB. [New York, Feb., 1870. 
15. Lepidium Virginienm, L.—That this species should have its coty- 
ledons accumbent, while others of the genus have them incumbent, 
seems somewhat anomalous. On picking the embryo carefully out 
of the seed coats, however, I find a conformation that in a measure 
removes the difficu'ty. In the species,which I have examined, viz., 
the present, L. ruderale, L. campestre, and, perhaps, L. intermedium, 
the cotyledons are continued, in the form of pefioles, about half 
way down the radicle; the cotyledons, in fact, being transversely 
folded upon themselves, as stated and illustrated in Gray’s Genera 
in the case of Subularia and Senebiera, the genera immediately 
“preceeding Lepidium. In the other species of Lepid:wm the plane 
of division between these petioles, or “radicular” portions of the 
cotyledons, is parallel to the cotyledons proper, and consequently 
to the seed partition.° In L. Virginicum this split is likewise paral- 
lel to the partition, and thus the “radicular” portions of the coty- _ 
ledons, is incumbent, and so far the species is in accordance with | 
its congeners. Where the cotyledons expand into a blade, they are 
turned sharply at right angles to the partition and become aceum- 
bent. If the embryo be held with the edge of the cotyledons — - 
towards the eye, it is the left blade which comes from the back of — 
the radicle, and thus has thelongerturntomake. Cakile Americana, — 
Natt., resembles Lepidium Virginicum in these particulars, except 
that the “radicular” portion of the cotyledons is relatively much 
shorter, and in one instance I found the blades of the cotyledons 
almost spirally bent over the radicle, so as to pass, as it were, 
through an incumbent stage. - 
I have also observed this narrowing of the cotyledons into a 
petiolar portion, greater or less, in Nasturtium, Cardamine, Arabis, 
Barbarea, Erysimum, and Raphanus, so far as represented in our 
Yoeal Flora; but in all these genera, the “radicular” split has con- 
formed nearly or quite to the cotyledons, as they are incumbent or 
accumbent: in Cardamine it is long and somewhat inclined to one 
side. I borrow the application of the term radicular from Gray's 
Genera, to which admirable work Iam indebted for much instruction 
on the subject of Crucifers. The term, however, when applied to 
the cotyledons, is open to objections. 
Perhaps my experience in picking out the embryos may be of 
use to beginners, I boil the seeds for a moment in a porcelain saucer 
over a spirit lamp to soften the coats, and then, with needles in- 
nee in a holder, and a fixed lens, have peal difficulty _ 
getting at the embryos by picking the coais to make an opening, 
and then carefully poo ile nace out. In the case of Le- 
pidium, however, there is a difficulty. Immersion, particularly a 
t water, causes the mucilage with which the seed coat is charged, — 
to swell and envelop it in a beautiful crystal sphere, much larger | 
than the seed itself. This slippery substance interferes sadly with 
he handling of the seed. It as be rubbed off, but I find it better 
to exclude the water by boiling the pods entire. The seed of L. a 
Campestre has a very thick coat, and can not readily be picked to— 
Cat from the end, without injuring the embryo, which may then be — 
‘Squeezed out. Considering how many seeds a well grown cepidlium 
