Prof. Link on the Structure of the Orchidacee. 39 
searches were made on Cypripedium spectabile, as the commonest 
species in our gardens. When we examine a transverse section 
of the column, it may readily be imagined that the two anthers 
are actually separate. There are three vascular bundles around 
the stigmatic canal, and besides these, another above and one on 
each side, as if belonging to two anthers. But we see just the 
same in Calanthe veratrifolia, to which we certainly cannot ascribe 
two separate anthers. As a general rule however, there exist 
other vascular bundles besides the three situated around the 
stigmatic canal ; these have already been spoken of. 
In regard to the stigma, there is no doubt that we must, with 
Robert Brown, call it three-lobed. In every transverse section 
made through the column, we find a triple excavation of the 
stigmatic canal. These excavations are often divided again. Thus 
we find it in Gongora maculata, of which I have given a mag- 
nified representation im the Anatomical Plates (Heft i. tab. 20) ; 
_ also in Stanhopea eburnea and Mazillaria macrochila, &e. Lind- 
ley’s view that the capsule is composed of six carpellary leaves is 
confirmed by transverse sections at the apex of the germen. 
I have nothing new to add to what I formerly made known 
relating to the remarkable structure of the germinating embryo 
(Select Anatomico-Botanical Plates, part 2. pl. 7); and I still 
believe that the embryo is not a tuber, in its rudimentary con- 
dition, but is nevertheless formed in an analogous manner. 
It might be said that the formation of tubers is an especial 
peculiarity of the Orchidaces, for when the roots are not tuber- 
ous, the stem strives to become so. The pseudo-bulbi, as Lind- 
ley calls them, are tuberously-developed internodes. The in- 
ternal structure is the same as in the stem of Monocotyledons in 
general ; woody bundles are situated in a circle in a loose paren- 
chyma; only here, from the thickness of the internode, there are 
more circles than is usual elsewhere. A speciality occurs in 
these. Each woody bundle is composed, as usual, internally of 
spiral vessels, on the outside of which lie pseudo-porous vessels ; 
to these follow pseudo-porous parenchymatous cells which be- 
come successively narrower, and at last appear as prosenchyma- 
tous cells ; at the outvide, where the larger parenchyma begins, 
he the tubercular tubes of which I will speak immediately. To- 
ward the interior, near the axis of the tuberous internode, we 
find the same series, only the pseudo-porous vessels are wanting. 
Those tubes which I have mentioned are relatively rather wide, 
without transverse septa, so far as I have examined, and, at re- 
gular intervals, stand elliptical papille surrounded by a rim of 
the same form. At first sight they appear like the common so- 
called pores or bright spots, but they project distinctly from the 
front of the tubes, and are more or less filled with a dark gra- 
