1885.] NATURAL SCIENCES OF PHILADELPHIA. 117 



Influence of Temperature on the Separate Sexes of Flowers. — 

 Mr. Meehan referred to his former observation, recorded in the 

 Proceedings, that the male flowers in Amentaceae, and other 

 dioecious plants would grow, become perfectly developed, and 

 mature the pollen under a temperature wholly insufficient to 

 excite the growth of the female flower, which would remain 

 undeveloped until a warmer temperature ensued. He had shown 

 that the infertility of hickories, oaks, walnuts, hazelnuts, and 

 other plants, a complaint common among orchardists in our 

 country, arose from this fact, there being very little or often no 

 pollen to fertilize the flowers in seasons when a few moderately 

 warm days in winter would bring the aments to perfection a 

 month or even months before the female flowers grew. This 

 season we had no warm winter days, and at this time, middle of 

 April, the aments in the hazelnuts and the female flowers were 

 maturing together. 



Mr. Meehan added that when he first reported these observa- 

 tions to the Academy he believed them wholly original, but he 

 had since noted that similar observations had been communicated 

 to the Horticultural Society of London, on the 18th of February, 

 1823, by Rev. George Swayne. " I entertain," says he, " a strong 

 suspicion that the xery frequent failures of the filbert crop (Mr. 

 Williamson tells us that they totally fail three years out of five) 

 are in great measure occasioned by a deficiency either in number 

 or in power of the male blossom." He remedied this by experi- 

 ment, by getting aments from other trees and hanging them in the 

 trees that had lost them. This gentleman, however, did not 

 apparently perceive the underlying principle that it took less heat 

 to perfect the male flowers than the female flowers of the same 

 species. It was quite possible this generalization might be 

 carried out of the region of amentaceous or allied plants, and 

 carried to a wide range of vegetable species, or even into zoology. 



April 28. 

 Mr. Edw. Potts in the chair. 



Fourteen persons present. 



A paper entitled " On the genus Aphredoderus," by Willis S. 

 Blatchley, was presented for publication. 



Mr. Philip Laurent and the Rev. J. R. Danforth, D. D., were 

 elected members. 



Elasticity in the Fruit of Gactacese. — At the last meeting of the 

 Botanical Section, Mr. Thomas Meehan exhibited fruit of Mam.il- 

 laria Heyderi, and remarked on the elastic characters of this and 

 other species. This Mamillaria, under culture, flowers in April 



