SOME ABNORMALITIES IN PLANT STRUCTURE. 
M. S. MARKLE, Earlham College. 
In looking over large numbers of microscopic slides made during the 
past few years, I have noted many instances of abnormalities in struc- 
ture, some of which have not been reported, to my knowledge. Assuming 
that some of them may be of interest to members of the Academy, I 
submit drawings of a number of them. 
In cutting some fern prothallia of an undetermined species collected 
in the Washington Park greenhouse at Chicago, I noticed large numbers 
of imbedded archegonia and a few instances of deeply imbedded anther- 
idia. As will be seen from the drawings, these structures occurred 
several cells below the surface of the prothallium. An imbedded arche- 
gonium was generally associated with an ordinary one, though not 
always. The imbedded archegonium begins as a single cell, distinguish- 
able by its larger nucleus and denser cytoplasm. The axial row develops 
like that of an archegonium of the usual type, except that there are 
usually two neck canal cells, if such they can be called here, instead of 
the usual single binucleate one. This is perhaps due to the differences 
in the pressure of the surrounding cells. A variation in the imbedded 
archegonia was found in one instance, in which there were two arche- 
gonia, with the position of the cells in the axial rows reversed, as shown 
in the figure. 
Stages in the development of the imbedded antheridia were not 
found. 
In sectioning some ovaries of Lilium of unknown origin, I found 
several sacs in which the four free nuclei following the second mitosis 
all gathered at one end of the sac, instead of two at each end, as usual. 
One instance of a mature embryo-sac that had evidently resulted from 
the further development of such a condition as that mentioned above 
showed six nuclei at one end of the sac completely surrounded by walls, 
while two nuclei remained free. 
The “three-story” reproductive branch of Vaucheria shown in the 
figure was found in some material which was collected near Baton Rouge, 
Ala. The other, in which a secondary sexual branch was formed in the 
place of an oogonium, was collected near Earlham College, Richmond, 
Indiana. 
The megaspore tetrad of Selaginella shown in the figure shows the 
outer wall of the spore continuous around the group of spores instead 
of surrounding the individual spores. 
(117) 
