PROLIFICATION. 10] 
mation than the median form. If only the number of 
orders and genera be reckoned, the truth of this state- 
ment will be scarcely recognised ; but if individual cases 
could be estimated, the ditference in frequency between 
the two would be very much more obvious. ‘This may, 
perhaps, be explained by the fact that the branch has 
a greater tendency to grow in length than it has to 
develop buds from the axils of the leaves. The flower 
is admitted to be homologous with the branch, and it is 
also known that, up to a certain time, the branch-bud 
or leaf-bud and the flower-bud do not essentially differ." 
At a later stage the difference between the two 1s 
manifested, not only in the altered form of the lateral 
organs in the flower-bud, but in the tendency to an 
arrest of growth, thus hmiting the length of the central 
axial portion. Now, in prolified flowers the functions 
and, to a considerable extent, the appearance of a leaf- 
bud or of a branch are assumed, and with them the 
tendency to grow in length is developed. Median pro- 
hfication, therefore, in this sense, is a further step in 
retrograde metamorphosis than is the axillary form. 
To grow in length, and to produce axillary buds, are 
alike attributes of the branch; but the former is much 
more frequently called into play than the latter; for 
the same reason, median prolification is more common 
than the axillary form. This is borne out by the 
frequency with which apostasis, or the separation of 
the floral whorls one from another, to a greater degree 
than usual, is met with in prolified flowers. 
In both forms the adventitious growth is much more 
frequently a flower-bud or an inflorescence than a leaf- 
bud or a branch. This may be due to the position of 
the flowers on a portion of the stem of the plant espe- 
cially devoted to the formation of flower-buds, to the 
more or less complete exclusion of leaf-buds, 7. e. on 
the inflorescence. This conjecture is borne out by the 
comparative rarity with which prolification has been. 
observed in flowers that are solitary in the axils of the 
' Linn., ‘ Prolepsis,’ § vii; Goethe, ‘ Metamorph.,’ §$ 96, 103, 106. 
