1886.] 



NATURAL SCIENCES OP PHILADELPHIA. 



281 



inch long, the peduncles of course springing from the axils of the 

 upper leaves. Early in June a second growth occurs, on which 



are also female flowers. 

 On many of the stronger 

 a third growth is made 

 before autumn. The sev- 

 eral growths during the 

 season on this tree, have 

 no doubt had much to do 

 with its great size in so 

 short a time. The in- 

 volucre is a mass of loose 

 scales, in the centre of 

 which the four blackish 

 ligulate stigmas are seen. 

 Bisecting the flower verti- 

 cally, the usually minute 

 calyx segments, immediately beneath the stigmas are represented 

 here by numerous brown scale-like hairs, which simulate the scales 

 of the involucre, and are at the apex of a slender stipe or beak 

 four lines long, that seems to spring from the true ovarium as if it 

 were a true style, and the real pistils represent a four-cleft stigma 

 at the apex. He did not remember any American species that 

 had so long a beak in this early stage of growth, though there 

 were some species that he had not had an opportunity of dis- 

 secting. From those that he had had the opportunity of exam- 

 ining the differences in this feature were striking, and the 

 character could certainly be made more useful than it had been 

 in enabling us to discriminate species in this very difficult genus. 

 A horizontal section of the ovarium shows it to be four-celled, 

 with each cell two-ovuled. 



1. Peduncle with flowers, Quercus denfata, natural size 



2. Beak of the ovarium with stigmas enlarged. 



3. Beak of the ovarium with stigmas enlarged, Quer- 



cus macfDcarpa. 



June 29. 



The President, Dr. Leidy, in the chair. 



Eighteen persons present. 



A paper entitled " Notices of Nematoid Worms," by Dr. 

 Joseph Leidy, was presented for publication. 



Mineralogical Notes. Composition of Stromeyerite. Professor 

 George A. Kcenig placed on record the identification of Stro- 

 meyerite from Zacatecas, Mexico. At this locality the miners 

 designate the various silver minerals by their colors as black 

 silver, red silver, green silver, and blue silver. Under the 

 latter name plata azul several minerals are undoubtedly com- 

 prehended, but probably the most prevalent is the mineral 

 here identified as Stromeyerite. One 

 19 



large specimen is com- 



