HETEROTAXY. 189 
deviations from the customary arrangement of the in- 
florescence, such as the change from a definite centri- 
fugal form of inflorescence to an indefinite centripeta! 
one. This occurs occasionally in roses, where the 
shoot, instead of terminating in a flower- bud, lengthens 
and bears the flower-bud on its sides as in a raceme. 
In the hyacinth, the inflorescence of which is pro- 
perly indefinite, the terminal flower may frequently be 
found to expand first, though in order of development 
it may have been the last formed. 
It occasionally happens that certain plants will, 
contrary to their usual custom, bloom twice in the 
same season; this usually arises from the premature 
development of buds which, under ordinary circum- 
stances, would not unfold till the following spring. 
In these instances of what the French term ‘‘ fleuraison 
anticipée,”’ the position of inflorescence is not changed, 
but there are other cases where the position of the 
inflorescence is altered, as in the laburnum, where, 
in some seasons, racemes may be seen springing from 
short lateral “‘ spurs” along the sides of the branches, 
as well as from the extremities of long shoots. 
Of a similar nature are those cases wherein stems 
er branches usually sterile become fertile ; this happens 
in Hquisetacee,' in Restiacew, and other orders. In the 
equisetums, the condition in question has been specially 
noticed to occur after prolonged drought. 
Hawisetacee are likewise subject to an anomaly called 
by Duval Jouve interruption of the spike, and wherein 
the scales bearing the spore cases are separated by 
whorls of branches instead of forming one compact 
unbroken spike as usual. 
This alternation of the organs of vegetation and 
reproduction may also be seen occasionally in Typha, 
and other plants. 
Kirschleger describes a case in which the male cat- 
kins of Saliv cinerea were placed at the ends of the 
! Duval Jouve, ‘ Hist. Equiset. France,’ 1864, p. 154. 
