76 PLANT HYBRIDIZATION BEFORE MENDEL 



covered with fine "warty projections" (vermes deliees), "between 

 which the powder of the plants is carried externally, and spreads 

 its oil." (p. 16.) The stigma exudes also a secretion, which 

 Gleditsch considers to represent the contribution of the pistillate 

 plant to fecundation, as the "huile" from the pollen grains con- 

 stitutes the corresponding contribution of the staminate plant. 



"These two singular sorts of humidity, which are particularly filtered 

 in the flowers, and of which one exudes from the powder of the male 

 flowers, the other from the tube of the ovary, or from the style of the 

 female flower, unite and mingle together, whereby the one alters the 

 properties of the other and produces a substance of a third nature, which 

 participates in those of the two preceding, and which manifests itself 

 more or less in the young plants, after fecundation and propagation." 



(P- 17.) 



The actual process of fertilization, by means of this united sub- 

 stance, is stated by Gleditsch to be as follows : 



The most refined of these two fluid substances thus united, is 

 carried by suction into the ovary, where it enters the newly- 

 formed and undeveloped seeds, in a short time causing there, by 

 means of its proper force, a great change in the "pithy center" 

 (point moelleux) found there, i.e., within the ovules; furnishing 

 it (the point moelleux) its nourishment, and laying the founda- 

 tions for the final development of the young plant newly formed 

 there. It appears, therefore, according to the view here represented 

 (p. 17), that an undifferentiated central point of some kind is 

 assumed to exist in the ovules; that an oily fertilizing material, 

 exuding by degrees from the pollen grains, penetrates to the 

 ovary, generally by means of "canaliculi" often extremely min- 

 ute, enters the ovules, and reaches the "pithy center" referred 

 to as : 



"That part of the marrow or pith, which, coming from the plant, has 

 terminated in the ovary of the flowers." 



The fertilizing substance furnishes to this special "marrow" 

 the addition of a living fluid, which puts it in condition to extend, 

 and which is at the same time its first aliment, (p. 17.) We have 

 at the present time, he says, only a confused idea of the process. 



"We are not able to venture to judge it, except after the visible result 

 of expansion and development, of which we have just spoken." (p. 17.) 



This concludes the account of one of the most notable confirma- 

 tory experiments in pollination, conducted expressly for the pur- 



