GENEVA SOCIETY OF PHYSICS AND NATURAL HISTORY. 221 



Fol concludes from this that amoiifr the, Tiniicates, as weli as the 

 Siphonophora, there are swirniniDjj individuals and feeding individuals. 



The same member, in presenting to the society a copj' of his memoir 

 ou the Pteropods, gives some details of the Heteropods, which he is now 

 elaborating for his second volume, and proves, contrary to the opinions 

 of some writers, that the opening of invagination is persistent, and that 

 it becomes a mouth. This mouth once formed, the embryo swallows 

 the white of the egg; and this albuminous mass, after the hatching of 

 the larva, serves for food. 



M. Al. Ilnuibert communicated to tlie society the result of the study 

 of a blind Gammarus, found by M. Forel at the bottom of Lake Leman. 

 As no intermediaries have been found between the seeing Gammarus of 

 the lake at the surface of the water a;id the blind Gammarus which live 

 from the depth of 50 metres (IGO feel) to the bottom, M. Humbert does 

 not think it can be admitted that this Gammarus is descended from the 

 seeing species, and takes it for a variety of the GammarKs puteanus, a 

 species which dwells at the bottom of wells in the vicinity of the lake. 



Professor Bogdanow, of St. Petersburg, read to us a memoir ou the 

 successive history, through the difiereut geological ages, of the fauna of 

 European Russia, and accompanied his communication with numerous 

 explanatory maps. 



In additiou to the works mentioned above, a large number of reports 

 of recent and rare publications were made to the society, and a series 

 of less detailed communications were presented. 



M. Barbey gave some account of the Calilbrnia species of the genus 

 Upilobium, which he is now preparing lor the Kew Flora of California by 

 Mr. Watson. 



Prof. Alph, de Candolle took up and refuted the principal objections 

 offered by M, Schacht to t he theory of the sums of temperatures applied to 

 the phenomena of vegetation. The samegentleman informed us tliat Pro- 

 fessor Blytt, of Christ iania, made observations in Scandinavia, which con- 

 firmed his own made in our Alps, and which lead to this: that of the 

 valleys laid bare at the Glacial period, those whose glaciers retreated 

 first, present a richer and more varied vegetation than those which re- 

 mained a long time covered with ice. By consulting the notes collected 

 by the Rigaud family and the employes of the guild hall on the folia- 

 tion of the chestnut of Treille, at Geneva, M. de Candolle was able to 

 show that the time of the foliation does not vaiy with the age of the tree. 

 The same scientist described to us a colossal tree of California, 276 feet 

 in h( ight and measuring 20 feet in diameter, a section of whose trunk 

 was i)repared for tlie exhibition at Philadeli)hia, and whose age was 

 estimated at 2, i20 years. He gave us some details of the extent 

 of the culture of tea in the Indies, derived from the English journals. 

 He showed us a bunch of grapes, of half-white and half-red berries, and 



