38 THe MICROSCOPE. vr aN 
and the villi. In the fresh pollen temporarily mounted in balsam 
for immediate study of the surface, the extine exhibits the villi and 
the hyaline appendages conspicuously, but the shorter rounded 
papillze so slightly obtrude themselves on the observer’s attention 
that they seem to have been overlooked, or they may possibly have 
been mistaken for the bases of the hyaline appendages. 
In his “Notes on Pollen,” reprinted in the Monthly Micro- 
_ scopical Journal, for January, 1877, from the Gardener’s Chron- 
icle, Worthington G. Smith, F. L. S., refers to the pollen of 
Ipomea purpurea, giving the delineation here reproduced on a . 
smaller scale in Fig 6. : 
The extine is represented as studded with acute, conical 
spines, with no appearance of the villous surface, or of the summits 
of the smaller, intinal papille. The true aspect, as it seems to the 
writer, is more nearly like that of Fig. 1, the pollen of the “‘ moon- 
flower.” It is spherical, and varies in diameter from 5}; to 74> 
inch. ‘The transparent, colorless apendages, one of which is shown 
in Fig. 7, arise from the extine by short, narrow, cylindrical pedi- 
cles, each of which expands into a more or less obovate body, taper- 
ing to the somewhat obtuse apex, and slightly constricted near, the 
center. Their height is about ;,';, inch, their greatest width 
Tov 
The villi of the surface are finer and shorter than those of the 
Ipomeea Bona-nox, measusing zy'co inch in length. There is, 
however, no difficulty in demonstrating their presence. 
The papille originating from the intine, as they do in a way 
similar to those of the “moon flower,” are stout, with a somewhat 
constricted neck, and an evenly convex surface protruded beyond 
the extine, but scarcely beyond the villi. Their height is about 
svuv inch, their free extremities extending about wis7 inch 
beyond the extine; in Fig. 8, is shown the structure as it appears to 
the writer. 
IPOM@A BATATAS, LAM. (SWEET POTATO.) ' 
(Batatas edulis.) 
The pollen grains here differ from those of J. Bona-now, I. 
purpurea and I. pandurata, in the form of the extinal processes and 
the arrangement of the surface villi. The sub-hemispherical papillze 
are essentially similar to those of the species already referred to. 
The extinal processes are bottle-shaped, the base, or body, 
tapering slightly toward the basal origin, being subcentrally con- 
stricted, with rounded shoulders, and terminating in a narrow, 
