OF DIMORPIirC AND TRTMOKPFTTC PLANTS. 405 



only two plants (Exp. XXXII. & XXXIII.), which proved fully 

 fertile. 



JExp, XXXII. — This mid-styled plant was freely and legitimately 

 fertilized, during the rather unfavourable year of 1864, by nume- 

 rous surrounding legitimate and illegitimate plants. Eight cap- 

 sules yielded an average of 127'2 seeds, with a maximum of 144 

 and a minimum of 96 ; so that this plant attained 98 per cent, 

 of the normal standard. 



Exp. XXXIII. — This short-styled plant was fertilized in the 

 same manner and at the same time with the last ; and ten cap- 

 sules yielded an average of 113*9, with a maximum of 137, and a 

 minimum of 90. Hence this plant produced no less than 137 per 

 cent, of seeds in comparison with the standard. 



Concluding reinarJcs on the illegitimate offspring of the three forms 



o/'Ly thrum salicaria. 



Prom the three forms occurring in approximately e(jual num- 

 bers in a state of nature, and from the results of sowing seed 

 naturally produced, there is reason to believe that each form when 



legitimately fertilized, reproduces all three forms in about equal 

 numbers. Now we have seen (and the fact is a very singular one) 

 that the fifty-six plants produced from the long-styled form, when 



illegitimately fertilized by pollen from the same form (Class I.), 

 were all long-styled. The short-styled form, when self-fertilized 

 (Class II.), produced eight short-styled and one long-styled plant ; 

 and the mid-styled form, similarly treated (Class III.), produced 

 three mid-styled and one long-styled offspring ; so that these two 

 forms, when illegitimately fertilized by pollen from the same form, 

 evince a strong, but not exclusive, tendency to reproduce the 

 parent-form. When the short-styled form was illegitimately fer- 

 tilized by the long-styled form (Class IV-), and again when the 

 mid-styled was illegitimately fertilized by the long-styled (ClassV.), 

 in each case the two parent-forms alone were reproduced. As 

 thirty-seven plants were raised from these two unions, we may, 

 with much confidence, believe that it is the rule that plants thus 

 produced yield both parent-forms but not the third form. 

 When, however, the mid-styled form was illegitimately fertilized 

 by the short-styled (Class VI. )? the same rule did not hold good ; 

 for the seedlings consisted of all three forms, but in unequal num- 

 bers. Nor is this exception surprising ; for the illegitimate union 

 from which these seedlings were derived is, as previously stated, 



