On Abnormal Flowers of Solatium tuberosum. 81 
tapetum had become disorganized, and the sac contained numerous 
well-formed pollen-mother-cells. The same petal shewed a sac in 
the same position as that seen in longitudinal section of the flower 
mentioned previously. It was deeply imbedded in tissue on all 
sides and showed no signs of rupture. In this case the pollen- 
mother-cells were either about to divide or had just divided to form 
tetrads. 
Another flower (III) exhibited similar features. A swelling 
appears on the inner surface of the petal, containing a deeply 
imbedded pollen-sac with a few pollen-mother-cells. Some signs 
of a tapetum are visible, but no signs of rupture. The same 
section passed through the top of another pollen-sac evidently on 
the point of rupturing on the adaxial face. 
All flowers that shewed petals developing pollen-sacs had also 
the full number of fertile stamens. 
The material had unfortunately not been fixed for cytological 
examination, so that many points of interest relating to the 
structure of the pollen-mother-cells and the embryo-sacs of the 
anomalously-placed ovules, had to be left undetermined. The 
phenomena exhibited by these abnormal flowers appeared however 
to be sufficiently curious to warrant the publication of this brief 
note. 
DESCRIPTION OF TEXT-FIG. 11 (I.—VIII.) 
I. T.S. stamen near base, a, Ovules produced on the adaxial surface. 
II. T.S. stamen, semi-petaloid. 
III. and IV. T.S. petal shewing two pollen-sacs. 
V. L.S. abnormal flower, shewing (a) ovules on a stamen and ( b ) a 
pollen-sac developing on a petal ; diagrammatic. 
VI. T.S. abnormal flower ; diagrammatic. 
VII. T.S. same flower near base. 
VIII. L.S. stamen viewed from the adaxial side. The tangential section 
passes through the inward bulging filament and thus shews 
only the ovules at the apex of the ridge. The section is taken 
too near the axis of the flower to pass through the anther. 
