SEXUALITY IN PLANTS. 
371 
I hermaphrodite flowers the time at which an alteration of the 
“ environment ” occurs must be taken into consideration. As a 
j rule, the stamens are developed before the pistil ; hence if some 
|j check to growth accrue, it may occur before the formation of the 
1 pistil, when a staminiferous flower would result. Or, again, the 
circumstances inducing an arrest of growth at the period when 
the stamens are forming may subsequently change, and the 
pistil be regularly formed, though the stamens remain unde- 
veloped or abortive. 
That the precise period at which growth and development take 
place is an element of great importance in such matters, is one 
which no physiologist is likely to dispute. Not to mention 
I cases in the animal kingdom, it is sufficient to say that the 
conformation of flowers produced out of their accustomed 
season is very often more or less deranged ; their position is often 
different, their form changed, the number and arrangement of 
their parts altered. Of course the reproductive organs undergo 
I corresponding changes. The flowers of apples or pears which 
i are occasionally produced on the so-called midsummer 
' shoots ” have perfect stamens, but rarely perfect pistils. Under 
ordinary circumstances, the flowers we have mentioned are- 
developed in autumn, on short stunted branches or spurs, and 
remain quiescent till the following spring ; but in the cases 
, under consideration an imperfect flower is formed within a few 
weeks, at the end of a long, weakly shoot, also of rapid growth. 
I There is nothing surprising in this ; it is just what might be 
! expected, and it furnishes an illustration of our argument that 
the period at which certain changes occur is an element of 
I cardinal importance in the determination of the nature of those 
' changes. Baillon records having met with an hermaphrodite 
flower in June on the common hazel. It would be sufficiently 
extraordinary to meet with such a flower at any time, but it 
' seems more consistent to meet with such a flower in summer 
i rather than in winter, the normal period of flowering. 
The bearing that this part of our subject has on practical 
^ gardening is obvious, and particularly in the case of forcing. 
I Practical gardeners know well that in forcing vines, pines, straw- 
j berries, cherries, cucumbers, or indeed any plant which is required 
I to produce its flowers and fruit out of due season, they cannot be 
I too careful in the timely regulation and adjustment of the heat 
' and moisture at their disposal. Want of care, or deficient jiidg- 
} ment, will defeat the object aimed at, and a crop of leaves only, 
I or sterile “ blind ” flowers, or flowers which refuse to set,"” 
: will be the consequence. The anatomist knows the structural 
; reasons for this; the physiologist speculates on the causes 
1 which put the structures into action ; the practical man, taught 
I by experience, knows how to avail himself both of the one and 
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