22 PROCEEDINGS OF THE ACADEMY OF 



March 10. 



The President, Dr. Ruschenberoer, iu the chair. 



Twent3'-three members present. 



The following papers were presented for publication : 



" On the Anatomy of Ariolimax and other Pulmonata." By 



W. G. Binney. 



" Descriptions of some new species of Reptiles." By Edward 



D. Cope. 



Elevation of the Trunks of Trees. Mr. Thomas Meehan re- 

 ferred to remarks made on a former occasion not communicating 

 anything new to science but in regard to matter introduced into 

 a laAvsuit, as to whether the trunks of trees would elongate after 

 once formed. He suggested that trees growing on a rock, by the 

 natural thickening of the roots beneath, would lift the tree four 

 inches in forty years, which covered the matter in dispute. 



Since that time, however, Dr. Lapham, the Botanist, and State 

 Geologist of Wisconsin, had called his attention to a force at 

 work in elevating the trees of that region, which he believes had 

 not before been recognized, and which he thought of interest suffi- 

 cient to merit a notice in the Academy's Proceedings. This was 

 that frost gradually lifted trees so that the trunk would sometimes 

 appear in time to have elongated a foot or more. 



Since Dr. Lapham had made the suggestions, he had examined 

 trees in the vicinity of Philadelphia and found unmistakable evi- 

 dence that large numbers of trees had been raised iu the manner 

 stated. As was well known, most trees standing by themselves 

 had the collar of the tree of much greater diameter than the trunk 

 above; and the upper portions of the roots, springing from about 

 the collar, were considerably above the surface of the ground. 

 He had supposed, and he thought this was the impression of most 

 observers, that this arose merelj' from the annual deposition of 

 wood the thickening upwards of the roots but, on examination, 

 it could be seen in many cases that the axis, or original centre of 

 the root, once of course below the soil, was now above the surface. 



That tills was caused b^' the action of frost was probable from 

 what we know of its action on vegetation by what is known 

 as " drawing out." When the land freezes, expansion ensues, 

 drawing the clover root up with it, leaving, of course, a cavity 

 from whence the root was drawn. When tlie first thaw came, the 

 liquid, carrying earthy matter, entered the cavity; and thus the 

 clover I'oot was prevented from descending to its original position. 



