it 



127 ■ 



123. Marsilia quadrifolia in Massachusetts.— it seems to be the 



opinion of the most eminent writers^ on botany that the Marsilia 



quadrifolia is found in this country only at Bantam Lake, Conn. Dr. 



Gray makes such a statement in his Manual ; but in the Bulletin, iii, 



p. 3, he states that it is well established in Fresh Pond, near Cambridge^ 



Mass., although known to have been first introduced from Connecti- 

 cut, 



Prof, Meehan, in his '* Native Flowers and Ferns," writes that 

 doubt is thrown on its existence in Texas, of indeed anywhere but 

 in the one locality at Bantam Lake." In Sillimans Journal some 

 years ago Dr. Gray put the question : ''Is its rarity a sign that it be- 

 longs to a very old family about becoming extinct, or is it one of the 

 newer introductions of Nature, which has not yet had time to spread 

 here to any great extent." The latter supposition seems the more 

 probable, as I have found several comparatively large areas of the 

 plant in a remote part of the Charles River, above Dedham, Mass. 



The long distances of these habitats from settled districts forbid 

 the supposition that the plant was introduced there from Connecti- 

 cut, though that is not impossible. Its thrifty appearance gives no 

 indication that it is gradually dying out, but rather that it is spread- 

 mg. Not only does it take possession of a large water area in the 

 places where it was seen, but it encroaches a foot or more on the low 

 margin of the river, where the leaves, although densely crowded, are 

 very much smaller than those on the surface of the water. The 

 sporocarps seem to be most numerous just at the edge of the water. 



Roxbury, Mass. Henry L. Clapp. 



t 



124. GrowthofExogens. II.— Mr. John Foster, of Pleasant- 

 ville, pn intelligent member of the Society of Friends, and a practi- 

 cal nurseryman, after reading my article on the Growth of Exogens 

 published in the Bulletin of March, 1878, writes me as follows : '1 

 can scarcely say that I am a full convert to thy theory of the forma- 

 tion of rings in the growth of timber, or hardy trees and shrubs of 

 our climate, I have so often verified the correctness of the theory of 

 one rin^; in a year. There is one particular case to which I should 

 like to draw thy attention, A few years ago a tract of woodland was 

 cleared off which stood directly west of Robert Parson's house in the 

 village of Flushing, L. I., and, no doubt, has been frequently noticed 

 by thee. An old gentleman, a member of the Society of Friends, 

 told me that he recollected seeing it cut off by the British soldiers 

 during the Revolutionary War, when he was thirteen years old. At 

 the time it was cut off the second time, I counted the rings of many 

 of the cross-sections of the largest trunks and found that the number 

 of rings answered with wonderful regularity to the number of years 

 which had elapsed since the timber was cut before. Many of the 

 trees were chestnut, and we know that this genus sends up shoots the 

 next season after the parent tree is felled, hence we were enabled to 

 calculate with accuracy the age of the trees. I think very few trees 

 make a distinct second growth in the same season." 



I quote the above passage from Friend Foster's letter in order to 

 present both sides of this interesting subject, for the example cited 



