298 BOTANICAL GAZETTE [ NOVEMBER 
of the multiovulate type, use was made of Delphinium Carolinia- 
num Walt., and Caltha leptosepala DC. 
RANUNCULUS ABORTIVUS. The pistil first makes its appearance 
as @ slight rounded projection from the surface of the then 
small receptacle. This projection enlarges, as does the recep- 
tacle, until it is almost hemispherical. It then begins to elongate, 
and during this process a second, rounded projection appears in 
the axil of this as yet only slightly developed carpellary leaf 
(fig. 1). The second rounded mass of cells is produced asa 
result of the rapid division of the hypodermal cells, and is not 
epidermal, but is covered with epidermis. At this time a cross- 
section of the pistil shows that the upper side is slightly flat- 
tened. This flattening becomes more pronounced until, in a 
short time, the pistil is seen to be slightly concave above, 7. é., 
the edges of the carpellary leaf are beginning to fold around, 
eventually to meet to form a closed pistil (fig. 2). . 
In addition to this lateral folding, the outer part of the pistil 
soon begins to bend upward, until its apex, which was at first 
directed at right angles to the surface of the receptacle, now 
points in a direction parallel to it. The lateral folding, also, 
continues, nearly closing the upper part of the pistil (jigs. 3, 4)- 
In the meantime the axillary mass of cells has been growing, 
especially at the side towards the receptacle, causing its apex to 
turn away from the receptacle and down into the cavity in the 
upper part of the pistil, which has been bending upward, and 
towards the receptacle. It has now become possible to distin- 
guish two parts in the axillary mass of cells; a thicker basal part 
(which I will call the “axillary placenta,” since it arises in the 
axil of the carpellary leaf) and a slender apical part, the ovule, 
which bends down between the laminae and thus into the hollow 
of the pistil (figs. 5, 6). The axillary placenta itself is really 
not within the pistil, but forms part of the wall on the ventral 
side. The laminae of the pistil extend to it and are continuous 
with its outer layers of cells, and extend from it to the apex of 
the carpellary leaf, which has bent around almost in a semi- 
circle. When these laminae finally come together to close the 
