226 BOTANICAL GAZETTE. | September, 
Under S. nodosa H. Miiller23 says: ‘‘In most Lamiales 
and Personales the anthers lie in two pairs, one behind the 
other, and touch an insect visitor on the dorsal surface; the 
stigma then, to insure cross-fertilization, must also touch the 
insect on the back, and the style can scarcely lie elsewhere 
than between the two pairs of stamens, along the upper part 
of the corolla. The superior stamen comes in the way, and 
accordingly disappears; it has no chance of reappearing 
permanently, for it is directly injurious, and is weeded out 
by natural selection.” * * “Jn Scrophularia, on the other 
hand, the anthers come in contact with the ventral surface of 
the insect. The fifth stamen is thus useless but not injurious ; 
whether it be present or absent is of no im ortance, and it is 
therefore beyond the influence of natural selection. Accord- 
ingly, the small black scale-like appendage. on the upper 
wall of the corolla in Scrophularia, which represents the fifth 
stamen, shows not unfrequently more or less complete rever- 
sion to its primitive form.” It seems to me to be more con- 
sistent with the affinities of Scrophularia to suppose that the 
h 
Scrophulariacez and ‘* beyond the influence of natural selec- 
fon in Scrophularia. The antheriferous condition of the 
inally adapted to bees, which squeezed into the tube, and that 
, 
sorace tO the lower side, If the flower was originally shal- 
low, and was visited by insects lighting on the stamens,» 
eva why the upper stamen should have been left 
ind. 
he upper part of a narrow tube. 
ty to tendency to abortion of the stamens in sterne- 
Me Ems 
°3 Fertilization of Flowers, 434, 
