GARDENING AS A SCIENCE. 
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congeries of excessively small hollow cases, having to the eye the appearance of 
small dust. Each grain contains a mucilaginous matter, in which there float 
granules, often not exceeding the twenty-five tliousandth part of an inch in 
diameter. The female organ, or pistil, is a hollow case, of considerable size 
compared with the pollen grain ; it bears ovules, eggs, or young seeds in its 
interior, and is furnished at its apex with a lax, naked, secreting tissue, called the 
stigma. At the proper time the anther discharges its pollen, which, by contri- 
vances of various kinds, is made to fall upon the viscid stigma, to which it sticks. 
In that situation, each grain of pollen emits one or more fine transparent tuhes^ 
which plunge into the lax tissue of tlie stigma, and descend to the vicinity of the 
ovules, with which they eventually establish a communication through the 
foramen of those organs. Into the pollen-tube thus emitted, the molecular and 
mucilaginous matter originally contained in the pollen is discharged, and, passing 
along it, eventually arrives in contact with the ovule." 
Whether or not there be something purely imaginative in this description 
—the latter part of it particularly— we leave to the acumen of observant 
microscopic investigators to decide ; yet there is a general feature of truth in the 
leading points that every one who has paid minute attention to the hybridization 
of the Pelargonium and Gloxinia must, we think, admit. 
Let us advert to the white-blossomed species of the latter. Its stigma is a 
bold disc, glutinous, and therefore fully prepared to retain and act upon the 
tissue of the pollen grains. We never, in the course of ten years, witnessed the 
production of one ripened capsule of seeds. The blue varieties sometimes produce 
ripe seeds spontaneously; but the white {Gloxinia Candida)^ being almost 
destitute of farina, requires artificial impregnation, and this produces some fertile 
seeds. It has been said that there exists great uncertainty in attempting its 
impregnation by the farina of G. rubra ; but, whatever be tlie result as to 
variety, we have at this time several seed vessels well developed, by impregnation 
with the ruhra, among a multitude remaining entirely abortive, although each 
was touched with the farina of the same red species, transferred and applied 
liberally by means of a camel-hair pencil. 
As therefore, the process of artificial impregnation is uncertain in its results, 
failing with some blossoms and succeeding with others, though performed at the 
same time, and precisely in the same manner, it follows that the condition of the 
pistillum and stigma must be peculiar in order to insure success. This condition 
is one of maturity^ which can only be ascertained by great experience and minute 
individual observation. It is a study worthy the attention of the most intel- 
lectual physiologist, embracing one of the most refined theories of horticulture. 
It is the gardeners province to push the doctrine of impregnation to its 
utmost practical nicety ; the physiologist advocates theories and principles, which 
the practical man brings to the test of experience. We claim, therefore, the 
general admission upon strict principles of analogy, that no impregnation can take 
