294 BOTANICAL GAZETTE. 



cultivate, and which will amply repay investigation in many 

 more directions than agriculture and horticulture. 



7. Miss M. E. Murtfeldt read a paper upon the " Perio- 

 dicity of Sabbatia angulaiis," in which a period of seven years 

 was made out, the explanation of which was in vain sought for. 



8. Prof. W. R. Dudley presented a paper upon "An ab- 

 normal Orchid ; Habenaria hyperborea." It seems that the author 

 discovered many spikes of this species in which the flowers were 

 spurless, which fact was abundantly testified to by the display of 

 specimens. 



9. Prof. W. R. Dudley also spoke of the " Origin of the 

 Flora of the central New York lake region," giving it as his 

 opinion that the origin of the flora of this very peculiar region 

 must be looked for to the north and west. 



10. Prof. John M. Coulter read a paper upon the " De- 

 velopement of the Dandelion Flower," which was an embryolog- 

 ical study. The results obtained are noted elsewhere in this 

 number. 



11. Prof. W. J. Beal spoke of the " Leaves of the Gram- 

 inese with closed sheaths," bringing up several instances to illus- 

 trate the statement. 



12. Prof. J. C. Arthur spoke of "A supposed poisonous 

 seaweed in the lakes of Minnesota," a paper which probably ex- 

 cited greater local interest than any paper presented to the 

 section. The summer before Prof. Arthur had received speci- 

 mens of water from certain Minnesota lakes which seemed to be 

 fatal to cattle drinking it. The specimens were found to contain 

 an alga which is probably Rivularia fluitans. A visit to one of 

 the lakes showed these minute balls occurring in vast quantities, 

 forming a thick ecum on the surface. Such masses exposed to 

 the sun and decaying gave off an offensive odor, and in this con- 

 dition were apparently fatal to cattle using the water. In two 

 or three weeks the danger was past. If this be Rivulai'ia fluitans 

 it is its first discovery in America, though it is now found to be 

 quite generally distributed in Minnesota lakes Dr. Farlow, 

 Prof. Arthur and the writer found an abundance of it in Lake 

 Minnetonka. The author did not give it as his unqualified 

 opinion that the plants were poisonous, but that they seemed so. 



13. Joseph F. James read a paper entitled " The position of 

 Composite in the natural system," in which he very justly 

 claimed for Gamopetalm the most highly modified flowers, and 

 among them Composite? as of the highest rank. 



14. Prof. E. S. Bastin presented a paper entitled U A fact 



