340 Sexuality of Plants — Fecundation^ Hybridization. [August 



precise modus operandi of the fertilization of the ovary naturalists 

 are divided, and, according to their several opinions, have heen 

 classed under the respective appellations of ovarists, animalculists and 

 epigenesists. 



The Ocarisi maintains that the embryo pre-exists in the ovary, 

 and is fecundated by the agency of the pollen, as transmitted to it 

 through the style. 



The Animalcidist says : " that as the embryo is never found to 

 make its appearance till after fecundation, it must necessarily pre- 

 exist in the pollen of the anther, from which it is conveyed to the 

 ovary through the medium of the style, and afterwards matured. 

 According to this theory it is assumed that there pre-exists in the 

 pollen the seminal or male principle, and that this is conveyed to the 

 ovary, where alone it is capable of development. 



The theory of the Epigenesist is, that the embryo pre-exists 

 neither in the ovary nor pollen, but is generated by the union of the 

 fecundating principles of the stamen and pistil : the former being 

 the fluid, issuing from the pollen when it explodes, and the latter 

 the fluid that exudes from the surfice of the stigma when mature. 



These several theories have their respective adherents and de- 

 fenders, and the field is yet wide for examination and research, 

 through the medium of our present improved microscopes joined to 

 a most rigid analysis and close observation. Whether any one of 

 these theories be the true one, or whether the one finally approved 

 may not be a modification of the three, or yet entirely distinct, the 

 result to the practical cultivator is the same. The curious observa- 

 tions of Brongniart respecting the generation of plants seems to 

 throw quite a new light upon this interesting subject. He says: 



'• When the grains of pollen are placed in contact with the sur- 

 face of the stigma, they project their tubular appendage. The lat- 

 ter, when the surface of the stigma is naked, insinuates itself more 

 or less deeply within the utricles of the stigma. The granules of 

 the pollen quickly collect near the free extremity of the appendage, 

 which swell, and assumes a slight degree of opacity. The grain of 

 pollen then shrivels and withers. Soon after the extremity of 

 the appendage opens, and the granules of the pollen are laid bare, 

 and come in contact with the mucilagenous substance of which we 

 have spoken and which connects the utricles of the stigma. They 

 are then seen in little masses, which successively penetrate to a 

 greater depth in the direction of the style. When the utricles of 



