1902] NATURAL SCIENCES OF PHILADELPHIA. 643 



transpiral ion of water from the leaves. As an indication of this, 

 the tops of many of the trees have died. ** Before Columbus," 

 a cedar mentioned in the first paper, has been injured by the 

 disturbance of this nice balance. "Elliptical" is dead. 

 " United We Stand " is a fanciful name given to two united holly 

 trees. " The Union " is a growth where a cedar and a holly tree 

 have been joined by an ancient natural approach grafting. 



The STRA.ND AT Sea Side Park. 



Observation at this plact; on the New Jersey shore was conducted 

 in 1901, from August 24 to September 2. Kodeletzhya virginica 

 A. Gray was abundant in the converted salt meadow. It opens its 

 flowers for insect pollination early in the morning before 9 o'clock, 

 and closes them about 1 o'clock; for by 2 o'clock the flowers are 

 closed lightly. Hibiscus mosrheutos L. opens its flowers just after 

 sunrise, and the flowers remain open until about sundown, when the 

 petals begin to roll together. As will be shown in a subsequent paper, 

 this plant shows mutation, and in many respects corroborates the 

 statements of DeVries on the origin of species by mutation.^ The 

 changes produced in the flora by the grading operations on the 

 upper end of the strand are most marked. Eahinochloa crus-galli 

 (L.) Beauv. (Panicum cnis-galli L. var. hispidumY was abun- 

 dant, and associated with this grass in the graded areas of sand 

 Spartina polystachya (Michx. )L., Spartina patens (Ait.) Muhl. ; 

 while as a newly introduced weed, Linaria linaria (L. ) Karst. 

 (Linaria vulgaris Mill.) grew in association with one of the sand 

 grasses, Sieglingia purpurea ( Walt. ) Kuntze ( Tricuspis purpurea 

 A. Gray). Mollugo verticillata L. was found along the railroad 

 in abundance in 1901 and in the dune complex in 1902. Wherever 

 the areas burned over annually were left undisturbed in 1901, 

 there Rhus copallina L. grew with the utmost vigor, and this was 

 accentuated in 1902 upon a return to the beach after an absence 

 of a twelvemonth. 



The Hibiscus society mentioned in the previous report of the 

 strand at Sea Side Park was found in 1901 to be encroached upon 

 by Rhu^ copallina L. and Scirpus dehilis L., so that an admixture of 

 these plants took the place of the pure growth of the rose mallow. 



^DeVbies, Dte Matationstheorie. 



^ Names after Buitton, Manual of the Flora of the U. S. and Canada. 



