NATURAL SCIENCES OF PHILADELPHIA. 363 



October 7. 

 The President, Dr. Ruschenberger, in the chair. 

 Thirty-three members present. 



Laxo of Seed Germination in Swamp Plants Referring to a few 



brief remarks of Mr. Anhrey H. Smith, on a former occasion, in 

 regard to the naturalization of Taxodium dldichum on compara- 

 tively dry ground in tlie Northern States, Mi-. Thomas Meehan 

 said that it was an error to suppose that nature placed trees in 

 places the best suited to their growth. Almost all of our swamp 

 trees grew much better when they could get into dryer places, if 

 in ordinar}' good land. He referred among others to Magnolia 

 glauca, Acer rubrum, Celtis occidentalis, Ilex opaca, Cupressus 

 cliama^cyparis, Cepbalanthus occidentalis, Salix babylonica, espe- 

 cially as, within his own repeated observations, growing better out 

 of swamps than in them. Why it was that i\\ey grew in swamps 

 ^as no enigma to those in the habit of raising forest trees from 

 seed. It was found that seeds of these trees would only germinate 

 in damp places, and, of course, in a state of nature the tree had 

 to remain in the place where the seed germinated. 



He thought the principle taught that plants required water to 

 grow well was true only in so far as a humid condition of the soil 

 was concerned. Plants, as a general thing, though they were of the 

 class known especially as water plants, preferred to grow out of the 

 water, except in those which grew almost entirely beneath the sur- 

 face. He had found such plants as Polygonum amphibium and 

 some of the water-loving Ranunculi, grow much more luxuriously 

 in the terrestrial than in the aquatic state. As was well known, 

 the Taxodium distichnm in the southern swamps sent up " knees" 

 from various points as the roots extended, often as large as old- 

 fashioned bee-hives, and several feet above the surface. He had 

 observed that not only were the cypress trees at least as large and 

 luxuriant when growing in good, rather dry ground ; but the ten- 

 dency to throw up these knees was in a measure lost. They were 

 generally small, but often wholly wanting. With the general facts 

 before us of the antipathy of swamp plants to their watery fate, 

 he thought one might be safe in concluding that these root excres- 

 cences were the result of an effort of the plant to counteract the 

 law which, against its own desires, to speak metaphorically, had 

 found itself obliged by the necessities of its law of seed germina- 

 tion to be a denizen of a swamp. 



Mr. Aubrey H. Smith said : In connection with the observations 

 of Mr. Meehan, I think it worth recording that a few years ago I 



