Weismanris theory of Heredity (1891). 79 



same " ovary," but where we happen to be able to see 

 that a marked effect is sometimes produced on the 

 somatic-tissues of the mother by the pollen of the 

 father, there can be no question as to the male element 

 being able to exercise a direct influence on the soma 

 of the female. Consequently, whatever we may think 

 with regard to the case of animals, the facts with regard 

 to plants are in themselves enough to sustain the only 

 position with which we are concerned — viz., that the 

 male element is capable of directly modifying the 

 female soma. 



The facts with regard to plants are these. When 

 one variety fertilizes the ovules of another, not 

 unfrequently the influence extends beyond the ovules 

 to the ovarium, and even to the calyx and flower- 

 stalk, of the mother plant. This influence, which 

 may affect the shape, size, colour, and texture of the 

 somatic-tissues of the mother, has been observed in a 

 large number of plants belonging to many different 

 orders. The details of the matter have already been 

 dealt with by Darwin, in the eleventh chapter of his 

 work on 'Variation, &c. ; and this is what he says. 

 The italics are mine. 



The proofs of the action of foreign pollen on the mother-plant 

 have been given in considerable detail, because this action is of 

 the highest theoretical importance, and because it is in itself 

 a remarkable and apparently anomalous circumstance. That it 

 is remarkable under a physiological point of view is clear, for 

 the male element not only affects, in accordance with its proper 

 function, the germ, but at the same time various parts of the 

 mother-plant, i?i the same manner as it affects the same parts in 

 the semi?ial offspring from the sajne two parents. We thus 

 learn that an ovule is not indispensable for the reception of the 

 influence of the male element. 



