458 PROCEEDINGS OF THE ACADEMY OF [1881. 



in his botanical explorations, on the top of Lookout Mountain in 

 Tennessee; but there, as under cultivation, he failed to see a 

 single seed-vessel. He had been asked since, by a distinguished 

 Belgian scientific gentleman, whether he noted any plants among 

 the others which indicated a possibility of being recent seedlings. 

 It had not occurred to him to look especially for these ; but they 

 w^ould in all probability have been noticed if they had been 

 present. He said it was not to be inferred that because neither 

 lie nor others had found seed, the plant never produced them. 

 Experience with many other plants showed that they might be 

 barren for years, and then become suddenly fertile. It was more 

 than probable that long in the past these species were seminally 

 fertile, perhaps capable of self-fertilization, and that the infertility 

 of the flowers is a modern imbecility, which, as indicated in his 

 Detroit paper before the American Association for the Ad vancement 

 of Science, is the general concomitant of a species which has almost 

 run its race. That these two species rarely produced seeds in 

 modern times might be inferred from the fact, that though both 

 were very fertile in suckers, they were certainly limited to very 

 few locations. If with the power of producing seed to any 

 considerable extent, they would soon spread over wide areas. If 

 they had been deprived of the power of producing seed in very 

 far away ages, by the power of suckering alone they would 

 have been more widespread than they are. There seems to be no 

 other logical conclusion than that the plants once seeded freely ; 

 but that this power must have been long lost, to account for the 

 comparative limited areas to which the species are now confined. 



Perhaps the most interesting new facts noted are those connected 

 with the motion of the leaves in the two species named, as well 

 as in Rohinia jjseudacacia, though the most strongly marked in 

 Rohinia hispida. There is a diurnal as well as a nocturnal motion, 

 each in a separate direction. At a few hours before sundown, 

 each pair of pinna? are perfectly horizontal. The entire leaf is 

 perfectly flat. With sundown the leaflets begin to droop, till, by 

 dark, tliey are perfectly ])endent, the under surface of each leaflet 

 almost touching the under surface of the leaflet opposite to it. 

 With the advent of morning, the leaflets arise ; and soon after sun- 

 rise, the whole leaf is flat, as just before sundown, but they continue 

 to rise, till, by noon, the opposite leaflets have met above the 

 common petiole, almost touching each other by their upper 

 surfaces at midda}-, as they nearl}^ touch by their lower surfaces 

 \>y night. In other words, instead of traveling ninety degrees, as 

 do other plants the leaves of which "sleep "at night, these leaflets 

 make a daily circuit of one hundred and eighty degrees. 



Besides these novel facts, Mr. Meehan noticed what he could 

 not but regard as a case of paralysis. About the middle of 

 September, he noticed a sucker from one of his plants, which had 

 finished its growth for tlie season after having made about a dozen 

 nodes. While at midday the leaflets were erect, three leaves had 



