1884.] NATURAL SCIENCES OF PHILADELPHIA. 33 



open were found to have perfect seeds. If the plant with these 

 leaves, flowers and fruit had been found-in a state of nature, the 

 botanist would surely have made a new species of it, if indeed he 

 would not have had some doubts of a new genus. 



Mr. Meehan then referred to his contributions in the past, 

 tending to show that there was an innate tendency in plants to 

 varv; that this natural tendency was at the foundation of all 

 theories of evolution, and that environment had not near the 

 influence on variation some good botanists claimed for it. If we 

 were to take environment as a serious element of change, there 

 would be no certainty in the direction of change ; but a glance at 

 the palaeontological and other evidences showed that change had 

 been always in the direction of certain uni- 

 form lines, and evidently in accord with a pre- 

 determined plan, which the accidents of envi- 

 ronment hacl not been able to override. At 

 any rate, such illustrations as this of 

 the HaUsia showed a remarkable 

 change with which certainly environ- 

 ment had nothing to do. The seeds 

 were all from one tree, with not even 

 another individual of its own species 

 near it. The seedlings all came up jj fetrap- 

 in one bed together, and yet out of 'era, var. 

 many hundred seedlings, all with the same 

 exact conditions of environment, there was 

 n. tetraptera, var. j^^^^ Qj^g with even an approach to the 

 singular peculiarities of this. 



In regard to the sterility or fertility of plants, what we would 

 call environment had evidently' much to do, and this also he had 

 endeavored to point out in former botanical contributions. In 

 his paper before the American Association for the Advancement 

 of Science, at Detroit, in 1875, he had shown that Mr, Darwin's 

 experiments in keeping bees from clover, and which in England 

 led to sterility, did not so prove in Philadelphia, the protected 

 plants there being fertile; and he there made the suggestion that 

 the diflTerent conditions of environment led to the different results. 

 He had also since then shown that Linwm perenne in Philadelphia 

 was self-fertile, though in England Mr. Darwin had found that 

 one might as well apply so much inorganic dust to a pistil as the 

 flower's own pollen. Here we have another illustration. The 

 exuberance of vegetative growth being checked by age, or some 

 other circumstance of climate or season, acting against the vege- 

 tative and in favor of the reproductive principles —principles we 

 know by many illustrations were antagonistic — gave us this 

 season an environment for the first time favorable to fertility. 

 The figures are two-thirds the actual size. 



The following were ordered to be published : — 



