306 SOCIETY OF PHYSICS AND NATURAL HISTORY OF GENEVA. 



tural School of Peter tlie Gi*eat, a statement regarding tlie large quan- 

 tities in which the white truffle exists in the interior of Eussia. 



Dr. Mitller gave an account of the investigations of MM. Bornet and 

 Thuret respecting the fecundation of the Floridece, from which result 

 two exceptional facts in the vegetable kingdom : First. The effect of the 

 male element takes place here on a complete cellule, provided with a 

 cellulose membrane, and not on a i)rotoplasmatic rudimentary cellule. 

 Second. The result of the fecundation does not show itself in the cellule 

 which has received the contents of the antherozoids, the formation of 

 the fruit or cystocari) being produced at some distance in another part 

 of the female individual. To Dr. Midler also we were indebted for the ex- 

 hibition of specimens of a rare aquatic plant, of a fine rose-purple color, 

 found at Evian on the pebbles at the bottom of a spring of alkaline and 

 slightly ferruginous water. The plant is the RUdebrandtia rosa, var. 

 Jiuviatilis, Kutz, which, by its fructification as well as color, belongs to 

 the class, almost exclusively maritime, of the Floridete. On this occa- 

 sion the Eev. M. Duby spoke of another alga, which, as observed by 

 Dr. Welwitsch, covers at certain periods with a black crust the rocks on 

 the western coast of Africa. 



M. Duby read a note, accomiDanied by plates, on certain species of 

 exotic or little-known cryptogams. He describes fourteen new species, 

 and five but little known,' pertaining to seven different genera. Of the 

 new species one comes from the East Indies, three from Brazil, one from 

 New Caledonia, four from Mexico, three from Chili, and two from Aus- 

 tralia. On this occasion M. Duby stated that two new genera which 

 have been introduced seem to be of doubtful authenticity ; these are the 

 genera Amstremia and Bicraniella, which differ very little from the geuus 

 Dicranum. 3^he genus Campiloims has been separated from the genus 

 Dicranum by the two following characters : First, because the capsule 

 is gyrose at the base; second, because the galeas of fructification are 

 fimbriated at the base. Other botanists hold these characters to be of 

 no great value, and maintain that in the same genus species are found 

 in which the galea is fimbriate, and others in which it is not so. 



M. Duby has examined the microscopic vegetables which have covered 

 GUI' lake at certain points and which were presented by M. De Saussure, 

 on the part of Dr. Forel de Morges. They are grains of chlorophyllum 

 formed in the algse and deposited during rainy seasons on the soil, whence 

 they are borne by the waters to the lake. Dr. Miiller gave an account 

 of a memoir of.M. Schumann on the Besdemiacem of the high Tatra. 



The extraordinary warmth of the month of December, 1868, occasioned 

 in the month of February, 1869, the florescence wholly exceptional of 

 forty-six different species which have been observed in our environs by 

 M, Eeuter. 



§ 7. Zoology — Physiology. 



Madame Delessert and her daughters have merited our gratitude not 

 alone by the gift of the valuable herbarium already mentioned, but by 

 the rare collection of shells with which they have enriched our museum, 

 and which will be one of the finest ornaments of our future academic 

 buildings. This collection has not only the merit of being very rich in 

 remarkable si)ecimens, but possesses a special scientific value in hav- 

 ing served as a basis for the labors of Lamarck, who himself named 

 most of the shells then existing in the Delessert collection. The entire 

 donation has arrived without accident in our city and been deposited 

 Ijrovisionally in the municipal school of Saint Gervais. Two of our 



