420 Supposed Dimorphism of Lithospermum longiflorum. [June, 
These measurements are more readily compared when pre- 
sented in a diagrammatic form (see Plate). In this the length of 
the corolla tubes is indicated by the length of the vertical line 
measured from the bottom line to the mark -, the height of the 
anther by o, and of the stigma by x. For greater distinctness 
the similar points in all the flowers of each plant are connected 
by lines; the fine line thus indicates the variation in length of 
corolla tubes, the heavy one of the position of the anthers, and 
the dotted one, of the stigmas. The scale is magnified three 
times. 
The remarkably short style of flower No. 32, bore a distinctly 
two-lobed stigma, which under a lens was seen to be papillated. 
I think it was functional. In the case of flower No. 51, there is 
some doubt as to whether or not the stigma was functional; the 
shortness of the style may have been due to injury. In all other 
cases there were no reasons for supposing the stigma func- 
tionless. 
As it is well known that in cases of heterogonous dimanti the 
pollen grains of the two forms differ in size, I made many careful 
measurements of the pollen of flowers from seven different plants, 
and found considerable variation in size. The grains when dry 
are considerably elongated, being prolate-spheroidal in shape, but 
when wet they swell up and become spherical. The following 
measurements show the variations : 
F ace I to E pollen dry, prolate- aamen .025 X .035 mm. 
I llen dry, prolate-spheroidal....... 025 45°" 
- 16 to 20, pollen dry, eo abd: 025 % 035 
ig 21, pollen wet, spheroid 035 
“ 22, pollen dry, prolate-spheroidal .025 X .035 “ 
a 23, pollen wet, spheroidil Wiis Exe une "035 = 
a 52, pollen wet, spheroidal. : sss seses cos .042 g 
x §3, pollen wet, spheroidal. s sscsissess .039 “ 
a 54, pollen wet, Spberoidal, oe cs he saer .038 ve 
“«  5őto 59, pollen wet, sphervidal.,....... .039. oe 
“ 6o to 6T, pollen wet, — vos viwess -039 Let 
“ 62, pollen wet, spheroid .042 & 
It will be difficult to see, in these measurements, any evidence 
of dimorphism as to the pollen grains. It may be interesting to 
note here that the spherical pollen grains of the cleistogamous 
flowers have a diameter of only .025 to .027 mm. 
If now we compare the foregoing measurements with similar 
