BOTANY. 351 



TKAXS3IUTAT1ON OF SPECIES IN PLANTS. 



At the last meeting of the British Association, Prof. Henslow presented 

 the result of some experiments, in which he had so far succeeded in changing 

 the character of ^Egilops ovata as to lead him to conclude that M. Fabre's 

 original statement, that it was the origin of the domestic wheat, Triticum 

 sativum, was not altogether without foundation. He exhibited specimens, in 

 which the form of JEgilops ovata had undergone considerable change ; but 

 he had not yet succeeded in obtaining the characters of Triticum sativum. 

 Prof. Henslow then exhibited forms of Centaurea nigra and C. nigrescens, in 

 which it was seen that these plants had completely passed one into the 

 other. He then referred to instances of the species of Rosa, Primula, and 

 Anagallis. passing one into the other. 



Mr. Bentham stated that when he first began to study botany, he thought 

 permanent characters ought to be regarded as distinctive of species. He 

 now, however, believed that permanent characters might be given to plants 

 by locality and climate, which had no right to be regarded as distinct 

 species. He then proceeded to refer to his own experience of the Flora of 

 Europe, Asia, and Africa, as contrasted with that of the British Islands. He 

 instanced more particularly Bellis perennis and B. sylvestris as the same 

 plant, and Taraxacum obovatum and T. lo&vigatum. He thought that all the 

 forms of Rubus, with the exception, perhaps, of R. ccesius, ought to be 

 referred to E. fruticosus. Sir "W. Jardine referred to instances of birds in 

 which external circumstances changed the color of their plumage and other 

 points of their structure. Prof. Balfour referred to instances of plants which 

 varied very much in their characters, according to the circumstances in 

 which they were placed. He mentioned the case of Pontederia crassipes, 

 which assumed, according to its treatment, quite different characters. Acci- 

 dental changes in form frequently became permanent, of which he related an 

 instance in a fern at the Edinburgh Botanic Gardens. 



OX THE DEVELOPMENT OF THE EMBEYO OF FLOWERING 



PLANTS. 



In a paper presented at the last meeting of the British Association, Prof 

 Henfrey announced that Prof. Schleiden and Dr. Schacht had given up their 

 opinion that the end of the pollen-tube produced the embryo in the seeds of 

 flowering plants ; and had come to the conclusion that the embryo is formed 

 from a distinct protein mass, contained in the embryo sac. He also pointed 

 out that the embryo mass does not become a regular cell covered with 

 cellulose till after the pollen-tube has come in contact with the embryo sac. 



ON THE GER1TINATION OF SEEDS. 



In Lindley's Theory of Horticulture, it is stated that a M. Otto, of Berlin, 

 employs oxalic acid to make old seeds germinate. The seeds are put into a 

 bottle filled with oxalic acid, and remain there till the germination is 

 observable, which generally takes place in from twenty-four to forty-eight 



