GENERAL PRINCIPLES OF BREEDING. 75 



such an occurrence, from the temporary connection of the 

 flower with the stem, would be hardly possible." 



Yet, if the gemmules were given off by the pollen it 

 would be quite reasonable to expect such to be carried on 

 with the descending sap, and to modify the buds then in 

 process of formation, as they are represented to do the ovules 

 in the female ovary. But, as in the case of the blood, so in 

 that of the vegetable sap we have no evidence that it con- 

 tains particles possessed of plastic powers equal to the de- 

 velopment of tissue. This is affected only by the nuclei or 

 cells present in the substance of the tissues themselves; and 

 as these nuclei communicate or are continuous with each 

 other through minute branching processes, they easily affect 

 those immediately adjacent, but have comparatively no in- 

 fluence upon those that*are somewhat remote. The modifi- 

 cation, therefore, of the fruit capsule, pod, fleshy drupe and 

 fruit stalk surrounding the seed, is only what is to be ex- 

 pected from the contact of the male pollen with the cells of 

 the female flower, and. of these in their turn with those 

 adjacent, while all other parts of the plant are entirely un- 

 affected by the act. In the animal the process is identical 

 in every respect; the continuous cells maternal and foetal 

 rendered continuous or placed in direct opposition with each 

 other through their minute branching processes mutually 

 influence the vital processes and formative powers of each 

 other; and thus it comes that the nuclei of the womb, but 

 one step removed from its contained embryo, acquire certain 

 new characters from it, and in due time transmit these to 

 later progeny. The efficiency of this new inoculating pro- 

 cess will, of course, be greatest where the vascular connec- 

 tion is the most intimate; and, as we have seen, the effect on 

 the progeny is most patent when these points of intimate 

 vascular connection between mother and offspring are the 

 same in successive pregnancies. 



A correct view of this subject is of more practical im- 

 portance than may at first sight appear, for, although the 

 animal modified by the influence of the sire of an elder half- 

 brother is necessarily a cross, whatever the mode of exerting 

 such influence, an important question may arise regarding 



