THE FALL OF THE COROLLA IN VERBASCUM. 321 
and appears as if varnished. Owing to the above-mentioned 
phenomenon of irritability produced by a stroke given to the 
plant, the base of the sepals, contracting itself as we have 
already stated, presses against the annular projection; and, 
owing to its inclined position, the corolla is pushed forward and 
forced from the thalamus. In Verbascum sinuatum, as in some 
other species, the annular projection does not exist, but instead, 
towards the base, the tube of the corolla is rather swollen (fig. 3, c), 
and thence to as far as the orifice it ends in an inclined plane. 
Fig. 3. 
Besides this special structure of the base of the corolla, we 
must not leave unnoticed another kind of structure which is 
very important—namely, glabrescence or smoothness (almost 
amounting to polish)—which the lower and external part of 
the base of the corolla, covered by the sepals, presents to us. 
All this greatly facilitates the sliding of the sepals on the sides 
* 
