564 General Notes. [ September, 
thickly filled with pollen grains. These are colorless, finely dotted, and 
thin-walled, and they wrinkle up when drying. ; 
“The pollen grains of Viola mirabilis fall out from the anthers more 
easily and in greater abundance, and this may be regarded as of regular 
occurrence. The number of pollen tubes which run from the anthers to 
the stigmas is far smaller than in the other species spoken of, and the 
anthers are not so finely fastened on the stigma. Here, too, a part of 
the pollen will be pulled out by its tubes when the anthers are de- 
tached.” Von Mohl closes this part of the memoir by stating that, owing 
to the changes which the pollen of the late flowers undergo in drying, or 
on access of water, it has been impracticable to compare the pollen of 
the early large blossoms with that of the late, inconspicuous ones. 
farther states that in these late flowers fertilization by the pollen of any 
other flower is of course an impossibility. 
It may here be said that, as Timbal-Lagrave suggests, the characters 
of the late flowers of violets can be of aid in distinguishing species. 
Koch in his Synopsis has a section headed Flores Seriores Apetali, Later 
Blossoms without Petals. We do not know of any attempts other than 
those mentioned above to separate species by means of these peculiar- 
ities. 
In Kuhn’s Memoir, in Botanische Zeitung for 1867, a list of forty- 
four cleistogamic flowers is given, in which Viola is mentioned. 
Lastly, in Mr. Darwin’s new work, Forms of Flowers, 1877, the 
whole subject has received most careful attention. nite 
SILPHIUM LACINIATUM. — Sections of fresh leaves of Silphium lacin- 
atum, the compass plant, show that the parenchyma is compose a 
“ palisade tissue,” that is, of the tissue which occurs only immediately be- 
neath the upper surface in most leaves. : 
Not only are both upper and under surfaces provided with the tissue 
usually regarded as peculiar to the upper portion of the leaf, but the 
whole of the leaf pulp from one surface to the other is also composed 
it. There are often as many as six closely packed layers of palisade 
cells. — C. E. Bessey. 
SARRACENIA VARIOLARIS. — The experiments referred to in the June 
number of the Naturatist have been repeated by me several times of 
late, and with uniform results. At the last meeting of the. Botanical 
Section of the Boston Society of Natural History the experiments were 
again tried in the presence of the members. The results agreed at 
fectly with those detailed by Dr. Mellichamp. — B. M. Watson, JR- 
Botanica Papers 1x Recent Pertoprcars. — Flora, No. 16. # 
Pfitzer, Observations in Regard to the Structure and Development k- 
Epiphytic Orchids (dealing with the peculiar long cells in the pre 
rides, and with the occurrence of silicious dises in the pauto 
epiphytic orchids, continued in No. 17). Gandoger, New Roses 
eastern France. No. 17. Dr. Carl Kraus, Causes of the Unver- 
