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No. 84. The Pollen-Tube in some of the Cucurbitaceae, 
by Joseph Edward Kirkwood. 
NortH AMERICAN FLORA 
The Nortu American Fora, designed to include de- 
scriptions of all known plants native to North America, Cen- 
tral America and the West Indies, is being issued in parts at 
irregular intervals as rapidly as these parts can be prepared. 
ol. 7, part I, containing descriptions of the order Ustilag- 
inales by G. P. Clinton, was issued October 4, 1906. 
Vol. 7, part 2, containing descriptions of part of the order 
Uredinales is now in press. 
Lectures 
Pusiic Lecrures 
Two series of lectures have been delivered to the general 
public on Saturday afternoons, one in the spring and one in 
the autumn. These lectures were as follows; 
April 21. ‘*On the Correlation of Characters in Plants,” 
by Professor Hugo de Vries. 
April 28. «A Day at Hammarby, the Home of Linnaeus,” 
by Dr. W. A. Murrill. 
May 5. ‘‘A Historical Review of the Study of Fossil 
Plants,” by Dr. Arthur Hollick. 
May 12. ‘¢A Glimpse at the Development of Botany in 
America,” by Professor L. M. Underwood. 
May 19. ‘* The Effects of Radium on Plants,” by Dr. C. 
Stuart Gager. 
May 26. ‘‘Some Botanical Features of Porto Rico,” by 
Dr. Marshall A. Howe. 
June 2. ‘*Orchids; Their Botanical Features and Rela- 
tion to Horticulture,” by Mr. G. V. Nash. 
June 9. ‘*The Wild Vegetable Foods of the United 
States,” by Dr. H. H. Rusby 
June 16. ‘* The Origin and Adaptations of Desert Floras,” 
by Dr. D. T. MacDougal. 
June 23. ‘* The Botanical Exploration of the West Indies,” 
by Dr. N. L. Britton. 
