168 ALTERATION OF POSITION. 
escence is made up of collections of scales or bracts 
with no trace of floral structure. Fig. 79 shows this 
in a species of Willdenovia, and a very good example is 
figured in a bamboo, Pseudostachyum polymorphum, by 
General Munro.' 
‘** Rose willows” (fig. 80) owe their peculiar appear- 
ance to a similar cause, the scales of the catkin being here 
replaced by closely crowded leaves. These aggregations 
of scales or leaves are not confined to the inflorescence, 
but may be found in other parts of the plant, and may 
be frequently met with in the willow, birch, oak, &c., 
generally as the result of imsect puncture. On the 
other hand, the production of leaves or leaf-buds in 
place of flowers is, as is well known, generally the 
consequence of an excess of nutrition, and of the con- 
timuance rather than of the arrest of vegetative develop- 
ment.” It has even been asserted that a flower-bud 
may be transformed into a leaf-bud by removing the 
pistil at a very early stage of development, but this 
statement requires further confirmation.’ 
Viviparous plants—'l'he spikelets of certam grasses are 
frequently found with some of their constituent parts 
completely replaced by leaves, like those of the stem, 
while the true flowers are usually entirely absent. A 
shoot, in fact, is formed in place of a series of flowers. 
In these cases it generally happens that the outermost 
elumes are changed, sometimes, however, even the 
outer and inner palez are wholly unchanged, while 
there is no trace of squamule or of stamens and pistils 
within them, but in their place is a small shoot with 
miniature leaves arranged in the ordinary manner. 
1 «Trans. Linn, Soc.,’ xxvi, p. 142, tab. iv, B. 
2 «Si arbusculam, que in olld antea posita, quotannis floruit et 
fructus protulit, deinde deponamus in uberiori terra calidi caldarii, 
proferet illa per plures annos multos ac frondosos ramos, sine ullo 
fructu. Id quod argumento est, folia inde crescere, unde prius enati 
sunt flores; quemadmodum vicissim, quod in folia nune succrescit, id, 
natura ita moderante, in flores mutatur, si eadem arbor iterum in ollé 
seritur.’—Linneus, ‘ Prolepsis,’ § iii. 
® * Rev. Hortic,’ May, 1868, ‘Gardeners’ Chronicle,’ 1868, pp. 572, 737. 
