1893.] NATURAL SCIENCES OF PHILADELPHIA. 301 



the function of this honeyed secretion has utterly failed. At no 

 time have I ever seen a solitary insect visit these flowers. The 

 beauty of the involucre can only be seen by a strong lens. While 

 the nectariferous glands are larger in E. metadata, E. hypericifolia 

 has the larger and the prettier involucre. The observations were 

 made during September and October in Germantown. 



Dimorphic Forms of Lythrum Salicaria. 



An extended notice of the several forms of flower in Lythrum 

 Salicaria occurs in Mr. Darwin's "Forms of Flowers," pp. 137-248. 



My observations and deductions vary somewhat from those of 

 this eminent naturalist. I have noticed in my own general investiga- 

 tions that the behavior of plants is not always uniform at all times 

 and seasons. It is best to say that my investigations extended over 

 the four days of July 30, 31, and August 1, 2. The first three days 

 examination refers to a plant in my own garden — the last day to wild 

 plants half a mile away from my garden plant. 



The plant at this date had been in bloom for probably a month, 

 but the upper portion of the central spike, and the upper portions 

 of the lateral branchlets, were still growing and blooming freely. 

 The first observation was that the lower half of the central spike 

 was barren and the upper portion was seeding, but indifferently. 

 The lateral branchlets had every flower fertile. I set myself to 

 discover the reason for this difference. I found the flowers to be all 

 of what Mr. Darwin called his long-styled kind. Mr. Darwin 

 found the long-styled kind fertile though growing by itself. The 

 point is confirmed in this case, and yet there remained to be disclosed 

 why so many of the earlier flowers were infertile. In a three days' 

 close watching of this plant I found no insect visitors except one 

 Lepidopter. 



This seemed fond of the flowers, and numerous individuals of 

 the species were in constant attendance. I could not satisfy myself, 

 however, that the stigma was ever touched by it, and I suspected 

 some arrangement in the bud for self-fertilization. The style pushes 

 through the bud before the corollas expand and the glutinous 

 stigma is in receptive condition. On opening an unexpanded bud from 

 which a style had thus protruded, it was found that none of the anther 

 cells had become ruptured. Neither Mr. Darwin nor anyone appears 

 to have opened an unexpanded bud. The disposition of the style in 

 this condition is one of much interest. The upper portion represents 



