1888.] NATURAL SCIENCES OF PHILADELPHIA. 397 



same time of day as in the former case, I found the exudation as 

 abundant in the Cerastium also. Profiting by this hint, and exam- 

 ining at this time of day all species coming under my notice, I can 

 say that glands exist in Cerastium viscosum, C. arvense, Arenaria 

 serpyllifoUa, Stellaria longifolia, S. media; I could not find the 

 glands in Stellaria jnibera. 



It is well known that in Caryophyllace?e generally, there are 

 usually ten stamens, in two series, — the outer alternate with the 

 petals, — the inner five alternate with the outer, and opposite the 

 petals. There are often less by abortion, in which case it is the 

 members of the inner series that disappear. No glands are between 

 the stamens of the inner series. There are never but five, and these 

 alternate with outer stamens. The outer series mature the anthers 

 a day before the inner series mature them (except, I believe, in S 

 puhera) ; but the liquid exudation occurs with the maturity of the 

 anthers of the first series. 



The liquid (in the chickweed) has a slightly sweet taste, and is 

 very viscid, as a little taken out with the point of a pen-knife and 

 rubbed between finger and thumb, testifies. 



The five outer stamens in Arenaria serpyllifoUa bend inwards, and 

 the abundantly polliniferous anthers rest on the apex of the stigmas, 

 completely covering the stigmas with own-pollen. The inner ones 

 turn outwardly, resting on the petals or nearly so, and seem to have 

 anthers wholly destitute of pollen. In Cerastium viscosum., the pollen 

 matures before the pistils. At the time the pollen scatters, the fiisicle 

 of pistils are keeping close company. Soon afterwards they diverge, 

 push themselves up among the pollen-clothed stamens, and are cer- 

 tainly self-fertilized in most, if not absolutely in all cases. 



Examining the chickweed as it grew over a very large tract of 

 waste ground, and soon after noon, when with a close naked-eye ob- 

 servation the comparativelv large globules can be seen glistening in 

 the sun, — one can scarcely neglect asking nature the chief object of 

 this enormous production of sweet liquid, — for the collective quan- 

 tity from these millions of flowers may be truly styled enormous. 

 It has been asserted that nectar is given to flowers to attract insects 

 for the purpose of cross-fertilization, and many observations confirm 

 the deduction in numerous instances. Certainly the nectar attracts 

 and as certainly the visits often result in fertilization — sometimes 

 by the flowers' own pollen, oftener by the pollen from flowers on the 

 same or neighboring plants, and occasionally from flowers from 



