174 
HYBRIDIZING. 
The next point of moment to the desired end is to perform 
the operation at the exactly proper time, for it may be too soon 
as well as too late; a little observation will assist better in deter¬ 
mining this than anything that can be written. If a flower of a 
Pelargonium or Fuchsia be observed from the first expansion of 
the corolla, the style will scarcely be seen on the immediate 
opening, but in a few hours it will lengthen, till in the pelargo¬ 
nium it reaches the anthers, and in the fuchsia exceeds them in 
length; up till this time the stigma of both will be club-shaped, 
but as soon as it reaches a position favorable for the reception of 
the pollen, a remarkable change occurs : they each divide into the 
same number of lobes as there are divisions in the corolla, those 
of the first-mentioned reflex turning their points towards the 
anthers, and both exude a mucus by means of which the pollen, 
on its separation from the anther, adheres to the stigma, and is 
held until its office is fulfilled; the appearance of this gum on 
the stigma indicates the proper time for the application of the 
pollen in our crossing operations, and if this is not waited for, 
the immature condition of the style prevents the emission of the 
pollen tubes, while if it is allowed to pass by the stigma loses its 
power by age, and in either case fertilization misses. The period 
necessary for the passage of the pollen to the ovule differs greatly 
in various plants, nor can it be known except by the growing of 
the seed-vessel, and even then it is uncertain whether fertile 
seeds are contained in it, for the late Mr. Herbert found in some 
cases of hybridizing, that more than one application of the same 
pollen was necessary to ensure seeds capable of growing, and it 
may frequently be observed on one of the plants just named, the 
fuchsia, that though the berries swell to a considerable size and 
ripen, they have no perfect seeds; he was of opinion, the sti¬ 
mulus given by the first appliance of the pollen is absorbed in 
the completion of the seed-vessel, or the outer tissue, or frame 
of the seed, a continuance being necessary to endue it with 
positive vitality; this is a matter to which it is impossible to 
attach too much importance, for if the hypothesis be correct, 
attention thereto will remove the vexatious possibility of finding, 
on the examination of some carefully-crossed seed-vessel, nothing 
but skeletons, or “ light seed,” as it is called. 
With respect to the limits of muling, as little is known as of 
