310 BOTANICAL GAZETTE [NOVEMBER 
those genera in which the ripe achenes are furnished with hairs 
to aid in their distribution. Evidently under such circumstances, 
where they occupy a neutral position they would persist although 
not yet functional. 
The uniovulate types might be summed up as follows. These 
all represent a type of pistil in which an axillary structure 
appears, developing directly into the ovule in some cases, or in 
others forming an axillary placenta on which the ovule is borne, 
or in still others uniting with one lamina of the pistil and bear- 
ing at its summit an ovule. 
The multiovulate types are not sufficiently different to require 
discussion beyond the statement that they are probably developed 
from a modification of the last mentioned case among the uni- 
ovulate pistils. 
THE UNIVERSITY OF NEBRASKA, 
Lincoln, Nebr. 
EXPLANATION OF PLATE XXV. 
NotE.— All the figures were drawn by the author, by means of the camera lucida, 
with one or two exceptions, from sections 7 to 18m in thickness, cut upon a Reinhold- 
Giltay microtome. Some of the material was fixed with 1 per cent. chromic acid solu- 
tion, some in various gee chloride mixtures, and the remainder in various osmic 
acid mixtures, imbedded in paraffin, sectioned, and mounted in Canada balsam. All 
sections were stained on ihe slide, many different stains being used. The sections 
were examined by means of Reichert’s objective 8, and oculars 2 and 4. In making 
the drawings only the outer layer of cells or merely the outline is given 
hen not otherwise stated all sections called “longitudinal ” are aidan longitu- 
dinal sections. 
he magnifications given are those of the drawings, which were reduced one-half 
in engraving. 
Ranunculus abortivus L. 
Fig. 1. Longitudinal section of a very young pistil. x 565. 
Fig. 2. Cross section of a slightly older pistil. x 565. 
Fic. 3. Longitudinal section of a pistil showing the axillary mass of cells. 
% £65, : 
Fic. 4. Cross section of a pistil from the same flower as fig. 7, in the co 
a-a. X 565. 
Fig. 5. Longitudinal section of a pistil at the time of formation of the 
archesporium. X 565. 
