112 PROCEEDINGS OF THE ACADEMY OF [1883. 



The fact that F. suspensa makes abortive capsules freely, and 

 F. viridissima rarely, though it has the best developed pistil, 

 indicates that fertility is dependent on the potency of the pollen ; 

 and this is confirmed bj^ the production of capsules on F. viridissima 

 when the pollen of F. suspensa was applied : 



The fact that the speaker lias had both forms growing on his 

 grounds for many 3^ears, without any seed-vessel appearing on 

 F. viridissima, except in the case cited, shows that it is not likely 

 to be cross-fertilized through insect agency. 



In the fully fertile case of F. suspensa, the plants of F. viridissima 

 were fully four hundred feet away; and the suggestion of inter- 

 crossing between these forms, considered in connection with the 

 points previously made, seems to place hybridization out of the 

 question. 



We may conclude, therefore, that these two supposed species are 

 but sexually dimorphic forms of one ; and we have also the curious 

 fact that, in this case, notwithstanding the presumable influence of 

 the law of heredity, the strongly masculine tendency of the parent, 

 as indicated by the highly developed stamens, the potency of its 

 pollen on the F. viridissima. the power to almost perfect seeds in 

 l)artially developed seed-vessels generally, and the actual perfection 

 in one year, notwithstanding- the imperfectly developed pistil, 

 should have had to give way to the female tendency in the offspring 

 to such a great degree as to leave only four out of thirty-four to 

 represent the parent. 



Influence of Circumstances on Heredity. — Mr. Thomas Meehan 

 referred to the fact that seed of the purple-leaved variety of Ber- 

 beris vulgaris, collected from plants growing near Philadelphia, 

 reproduced the purple-leaved peculiarity to an extent which it 

 could not do more perfectly if the variety were a true species. 

 In a bed of seedlings, containing on an estimate one thousand 

 plants, there were onl}^ two reversions to the original green-leaved 

 condition. Two years ago, he had been given, by Prof. C. S. 

 Sargent, some seeds of ligneous plants, sent to him from some 

 European Botanical Garden, and of thirty seedlings planted only 

 two aie dark purple as in the parent. 



May 22. 

 Rev. Dr. H. C. McCook, Vice-President, in the chair. 

 Forty persons present. 



A paper entitled " A Revision of the Species of Gerres found 

 in American Waters," by B. W. Evermann and Seth E. Meek, was 

 presented for publication. 



