29 



Dr. E. B. Matzke gave a talk on "Variations in Stellaria 

 aquatica." The cotyledonary node of Stellaria aquatica com- 

 monly has two branches in the axil of each of the two leaves; 

 the two succeeding nodes more usually have a single one in the 

 axil of each leaf. From there on there is, as a rule, a single 

 branch in the axil of one of the two leaves at each node — the 

 leaf arrangement being decussate. Thus spirals are formed 

 by the branches; in 187 cases this spiral was counterclockwise, 

 in 197 clockwise, both types occurring on the same plant with 

 no apparent regularity in their distribution. 



The direction of the spiral is correlated with the overlapping 

 of the sepals in the first flower in the inflorescence; and the 

 arrangement of the sepals of subsequent flowers of the dicho- 

 tomous cyme is definitely related to that of the first flower. 



Variations occur in the number and character of the sepals, 

 petals, stamens and carpels; these variations occur with 

 noticeable regularity in certain positions in the flower. Thus 

 axes of symmetry are established in the flower which bear a 

 definite relation to similar axes in different flowers of the same 

 inflorescence. 



It is thus possible to establish the type characteristic for the 

 stem, the inflorescence and the flower, and the common vari- 

 ations from that type. 



There is a progressive seasonal sterility of the stamens in 

 Stellaria aquatica from the beginning of the flowering period 

 in July to its termination at the end of November. 



FoRMAN T. McLean 



Secretary 



Meeting of December 3, 1929 



The meeting was called to order at Millbank Hall, Barnard 

 College, at 8:30 p.m. by President Denslow. Ninety people 

 were present including a number of visitors from the teachers of 

 Biology in the schools. 



The following were unanimously elected to membership in 

 the club: 



Dr. Charles C. Deam, Research Forester, The Department 

 of Conservation, Blufifton, Indiana; and Miss Marjorie Swift, 

 The New York Botanical Garden, Bronx Park, New York City. 



