130 PROPAGATION OF PLAKTS. 



steep, and especially to the long known American 

 Merinos. No breeder of these sheep in the past fifty or 

 sixty years has allowed a black male in his flock, and yet 

 almost every season an ewe among the pure bloods, as 

 they are called, will drop a black lamb, a direct reversion 

 to some early ancestor of this color. 'No one can tell how 

 long, or through how many generations, this early con- 

 tamination will continue to show itself. Similar cases 

 of reversion, the result of contamination of blood, as it 

 may be termed, are known to frequently occur among all 

 of our domesticated and improved breed of animals, and 

 they are as likely to originate with and become hereditary 

 in the male line as in the female. As there is an afiSnity 

 between animals to admit of breeding, so there must be 

 the same among plants, and the mobile pollen promotes, 

 if it does not cause, excitability in the female organs of . 

 the flower, and thus produce a responsive action from 

 those below and beyond, as already stated. 



While it is not claimed that the influence of the pollen 

 will, in all cases, show itself in marked changes in the 

 form' or size of the pericarpic organs, still that it often 

 does this can scarcely be doubted by any one who has 

 ever made careful experiments for the purpose of ascer- 

 taining the truth in this matter. In cross-fertilizing 

 varieties of Indian Corn of different colors, the influence 

 of the pollen can be readily traced, not only in produc- 

 ing kernels on the same ear of different sizes, shape and 

 color, but the cob underneath the black, yellow or red 

 kernels will usually be tinged with a corresponding 

 color. In all plants having a distinct pistil for each seed, 

 as in Indian Corn, the Sorghums and Millets, or in fruits 

 like the Strawberry, Easpberry, etc., each and every 

 ovule must be fertilized in order to produce a perfect ear 

 or fruit. If none of the ovules are fertilized, the ear, 

 fruit, or pericarpic organs, and even supporting fruit- 

 stalk and stem, wither away. 



