* 
THE MICROSCOPE. - 35 
about the ;1, inch in diameter. The surface exhibits two forms of 
appendages, one kind being conspicuous at the margin as the grains 
lie under the lens, the others ‘being easily mistaken for the rounded 
bases of former. The conspicuous papille are irregularly scattered, 
more or less clavate in form, and entirely hyaline. On the general 
surface they are less readily seen than overlooked. The others 
appear as rounded prominences in more regular sequence, and form 
the most interesting portions of the structure, it being in these that 
the pollen in question differs from what is usually described by the 
by the authorities. And in addition to these appendages, the surface 
is finely villous. The extine is entirely covered with a short pile, 
like microscopic white velvet, and through this plush-like covering 
the clavate and rounded papille project (see Fig. 1). This velvety 
surface has never before been observed on any pollen, so far as I 
know, although it is noticeable on a very common plant. 
The constituent filaments of the fringe, or pile, are thickened 
and variously curved. They seem to be rigid, and adherent to each 
other, since no manipulation to which I have subjected them has 
been followed by their separation, or by the pliant motions common 
to a velvety surface under pressure. They arise directly from the 
surface of the extine, and measure ;;,, inch in length. 
The clavate hyaline papille take their origin from the same 
membrane, through a narrow base followed by a constricted pedicle 
scarcely longer than the surrounding fringe-like appendages, the 
foot-stalk expanding into a more or less ovate, anteriorly taper- 
ing body (Fig. 3). Their perfect, colorless transparency would 
render any granular or semi-opaque contents plainly visible, but I 
have seen nothing within them, even under an amplification of two 
thousand diameters. Their contents must be a thin, strictly homo- 
geneous fluid. Their length averages about ;,'5; inch. The great-- 
est width is about ;,'5> inch. 
No special preparation, except mounting the fresh grains in 
balsam for immediate study, is needed to show that their structure 
differs from that described in the books, for pollen in general. The 
special points of divergence are obscure under that simple treatment, 
but enough is divulged to excite interest and urge to further investi- 
gation. Ifthe pollen grains are treated with alcohol, the protoplasm 
will be coagulated, when pressure will rupture the coats and foree 
out the thickened contents, and if a large quantity thus treated is 
mounted in balsam, some grains will accidentally take the proper 
position to show the structure. Through the kindness of Dr. W. P. 
