202 Botanical Society of Edinburgh. 



of the chest and that of the breast are black : there is a broad 

 black stripe along the abdomen : the feelers are black : the nec- 

 taries are pale yellow with black tips, and less than one-fourth 

 of the length of the body : the legs are pale yellow ; the knees, 

 the feet, and the tips of the shanks are black. 



Variations of the wing -veins. 1st var. The first vein, the lower 

 branch of the first fork, and (with the exception of its tip) the 

 upper branch of the second fork of the third vein, are wanting. 



2nd var. The second vein has near its tip a fork which does 

 not join the border of the wing. 



3rd var. The second fork of the third vein is close to the tip 

 of the wing. 



[To be continued.] 



PROCEEDINGS OF LEARNED SOCIETIES. 



BOTANICAL SOCIETY OF EDINBURGH. 



June 14, 1849. — Professor Balfour, President, in the Chair. 



Donations to the library were announced. Specimens of the va- 

 rious species and varieties of tea cultivated in Assam were presented 

 by Dr. Jameson ; and Himalayan ferns by Mr. Wyville Thomson. 



The following papers were read : — 



1. '• On Nostochinece" by Messrs. Ralfs and Thwaites. This 

 was a continuation of a former paper, being descriptions of the spe- 

 cies of Trichormus, Aphanizomenon, and Dolichospermum. It will 

 appear in the ' Annals of Natural History ' and the Society's 

 ' Transactions/ 



2. " Remarks on the Origin of Plants and the Physical and Geo- 

 graphical Distribution of Species," by the Rev. Dr. Fleming. The 

 author stated that it had been assumed as a first principle, con- 

 nected with an extensive series of speculations in botany and geo- 

 logy, that species had sprung from single centres, and that the indi- 

 viduals had ** radiated from one point to greater or lesser distances 

 around it," according to Dr. J. Hooker; or that all the individuals 

 of a species could be traced " from a single progenitor, or from two, 

 according as the sexes might be united or distinct," and hence the 

 origin of the phrase, *' specific centres." In opposition to this view, 

 it was stated, that the history of the human race, traced to their 

 origin in a single pair, did not furnish an analogical argument of 

 any value ; while the dependence of the carnivorous animals on the 

 herbivorous kinds, and the latter, along with man himself, on plants, 

 gave good grounds to conclude that many individuals, of grasses for 

 example, were requisite in the first instance, and were brought forth 

 abundantly. These considerations rendered the assumption of " spe- 

 cific centres " extremely improbable ; but the occurrence of similar 

 species, in localities remote from one another, and even in opposite 

 hemispheres, over which, by no conceivable process, could dispersion 



