* 
143 
Through northern Mexico species occur showing successive 
modifications in these characters until one finds the following 
condition in the Pectinatae and Cassioides of the southeastern 
United States. The corolla is rotate, its lobes much longer than 
the tube, glabrous within (irregularly slightly pubescent in 
Pectinatae); the filaments are flattened and pubescent for only a 
slight portion at the base, and filamentous nearly throughout; 
the anther-sacs open by slits extending never over one fourth 
their length, suggesting a terminal pore. 
Although they are alike in flower-structure, the differences in 
the leaves, fruit, and seeds of the Pectinatae and Cassioides place 
these in divergent lines of evolution. The intermediate species 
group themselves on one or the other phylogenetic stem. Afzelia 
illustrates not only progressive evolution, with progressive 
removal from the geographic point of origin, but exhibits this 
in two lines of advance and thus affords a remarkable case of 
parallel evolution. 
A. B. Srovt, 
Secretary of the Conference. 
SUMMER LECTURES, 1919 
The following program of public lectures has been announced 
for the summer of 1919. As usual, they will be held in the lecture 
hall of the Museum, Saturday afternoons at four o'clock. 
June 21. “Edible Wild Mushrooms,” by Dr. W. A. Murrill. 
June 28. ‘Some Books on Gardening,” by Dr. J. H. Barn- 
July 5. “Why and How to Spray Plants,” by Dr. E. B. 
July 12. “Dwarf Fruit Trees for Suburban Homes,” by 
Capt. F. A. Waugh. 
July 19. “Rose Gardens,” by Mr. George V. Nash. 
July 26. “Attractive Flowering Plants of New York State,” 
by Dr. H. D. House. 
Aug. 2. “Floral and Scenic Features of the Island of Jam- 
aica,”’ by Dr. Marshall A. Howe. 
