1890.] XATUKAL SCIENCKS OF I'HILADICM'llIA. 260 



paratively high temperature, ^Yllile tlie female organs continue (qui- 

 escent, scarcely needed further confirmation, the present additional 

 point that under a prolonged moderate temperature the female will 

 advance more than the male has not been brought out so well befoi-e. 

 This, in the hazel-nut or filbert, has never been noted in America here- 

 to-fore to the best of my belief. So unexpected was the fact as to 

 make a statement in the Transactions of the Royal Horticultural Soci- 

 ety of London, vol. V, 1824, p. 311, appear almost incredible to one 

 not familiar with such observations as I have recorded. The Rev. 

 Geo. Swayne says at the i^age quoted " casually passing by them (the 

 trees) in the second week in February, 1820, 1 was rather surprised 

 to see a considerable number of scarlet blossoms thereon in a state 

 of expansion, but at the same time very few catkins, and tho.se few 

 seemed to be in a very imperfect state, not a single one being pre- 

 pared to discharge its farina." Here we have a precisely similar 

 observation in these Philadelphia plants, only four weeks earlier 

 than Mr. Swayne saw them. 



The season has been one of the most remarkable known for many 

 years. Instead of the thermometer varying from the the freezing 

 point to zero, with occasional spells of a day or two between at 50° or 

 60°, the thermometer has only once fallen just beneath the freezing 

 point, while at no time has it risen above 50°. The general remark 

 with English people is that it is an open English winter. The 

 English hazel, therefore, finds itself pretty much at home, and has 

 fallen back on its natural habit, as we may suppose, of producing 

 both sexes nearly simultaneously. 



The deductions from former observations may again be re])eated : — 



Under sudden high temperature the male flowers of the hazel will 

 open and perfect, long before the female flowers are affected by the 

 same temperature. 



Under long continued temperate heat, the female flowers will 

 advance more rapidly than the male. 



There is no specific rule in dichogamous plants. A plant with 

 flowers proterandrous in one season or one country, may be pro- 

 terogynous in another. 



My former observations were made on various flowers, though 

 confined to the hazel in this paper. 



DiOECissM IX Labiat.5-:. 

 In some observations recorded last year I noted that the sexual 

 disturbances observed in some European Labiate, did not seem to 



