Inheritance of Mutation in the Common Foxglove. 49 
lower nodes develop in most cases into short shoots bearing a few 
leaves below the flowers. At the succeeding nodes, as a rule though 
not universally, the shoot is replaced by a single flower bud which 
does not reach full development. Some of these buds remain quite 
rudimentary, others develop further and may produce functional 
organs ; but even in this latter case growth ceases while the parts 
are still enclosed in the calyx. Afterwards follow the fully developed 
flowers which continue to near the top of the spike, where they may 
again be replaced by buds which never unfold. It may happen f 
however, that no buds are arrested at the base of the spike, in which 
case the full-sized flowers follow immediately upon the leafy shoots. 
Only a few of the heptandra individuals exhibit a complete 
absence of petal-like structures throughout the whole of the inflorescence', 
though now and again an individual will be found to show this 
condition from top to bottom of the spike. In these cases the 
apparently total absence of corolla gives the spike a very curious, 
albeit, quite uniform appearance. In the great majority of the 
plants, however, it is noticeable that in travelling up the spike the 
flowers present a graduated series ; dialysis and staminody of the 
corolla gradually diminish, and reversion may even be carried so far 
that eventually normal flowers are produced near, or at the top of 
the inflorescence. This increasing tendency towards normality may 
extend to the summit of the spike, or it may reach high-water mark 
below, but so near the apex, that whatever stage in the progressive 
series is reached at this point is maintained upwards to the top. In 
other cases the wave may spend itself some distance below the 
summit, and the later flowers then form a downgrade series ending 
in partial, or occasionally, if arrested flowers occur in this region, 
in complete return to the extreme heptandra condition 
The choice of the name heptandra, as it proves, is not altogether 
happy, for although it correctly describes the condition occurring in 
the great majority of the flowers ( i.e ., those having the three petals 
of the lower lip replaced by three stamens more or less similar to 
those of the androecium proper, thus making seven stamens in all), 
it is not strictly applicable in those cases where a greater or lesser 
degree of deviation from the normal occurs. Thus, on the one 
hand, almost every stage may be found between the true heptandrous 
condition and the normal flower with four stamens; while at the 
other end of the scale we meet with the extreme case in which both 
lips of the corolla are replaced by stamens, so that nine (or rarely 
ten) stamens are present, and the flower appears to lack all five 
