296 PROCEEDINGS OF THE ACADEMY OF [1893. 



From this time until near noon the next day, everything seems 

 absolutely at rest ; but at 11 A. M., the corolla again expands so as 

 to be widely campanulate, and the pistils are found advancing 

 beyond the line of the anther cells, carrying along Avith them the 

 comparatively large pollen grains that had been deposited the day 

 before. By 1 P. M., the corolla has again closed, drawing up and 

 closely pressing the pistils and the anther cells together. It is at 

 this period of the observations that the most beautiful phenomenon 

 of the whole may be observed. Along the inner face of the style 

 from apex to base is a single line of minute hairs. The pollen 

 grains attach themselves to these hairs and are thus arranged in a 

 single line like bright pearls along a curved silken thread. Dr. 

 Ida A. Keller, who has kindly repeated some of the observations I 

 here record, finds indications of pollen tubes entering the pistils 

 through the papilla? or hairs. 



On the third day, toward noon, though the petals remain closed, 

 the pistils will be found withering, and the carpels enlarging, thus 

 indicating that fertilization has been accomplished. 



In the Proceedings of the Academy, 1889, page 55, in a paper 

 entitled " On Secund Inflorescence," I have shown that in a number 

 of flowers with a convolute aestivation, the spiral line in closing is 

 directly the reverse of that followed in the opening. A surprising 

 fact was noted in connection with this Malva that in closing, the 

 twist might be either from left to right or right to left — both lines 

 existing on the same plant. All attempts to form an hypothesis 

 accounting for this remarkable behavior failed. 



One fact strongly developed by these observations is that fertili- 

 zation may be accomplished before the pistils have completed their 

 growth, thus confirming the observation of Dr. Ida A. Keller in her 

 paper on Monarda fistulosa in the Proceedings of the Academy, 

 1892, p. 452. 



The Peduncle in Streptopus amplexifolius. 



The point I have strongly presented in connection with " extra- 

 axillary " branches, that these are but arrested leaders which have 

 been supplanted in leadership by the strong growth of the axillary 

 bud, is remarkably well illustrated in Streptopus amplexifolius. Dr. 

 Asa Gray says of it " it has small (extra) axillary flowers, either 

 solitary or in pairs, on slender thread-like peduncles, which are 

 abruptly bent or contorted near the middle." And further, " the 

 peduncles, as in the next, are opposite the leaves, rather than truly 



