Botanical Society of Edinburgh, 181 



/■mtnoiii 



BOTANICAL SOCIETY OF EDINBURGH. 



May 8, 1856. — Colonel Madden, President, in the Chair. 



The following papers were read : — 



1. '*0n the Sexuality of the Algae," by Dr. Ferdinand Cohn, of 

 Breslau. 



After adverting to the various recent discoveries in Cryptogamic 

 reproduction, particularly those of Thuretand Pringsheim, the author 

 gave an account of the pheenoraena observed by him in Sphceroplea 

 annulina. He showed that the cells of one part of the filament be- 

 came male, and exhibited antheridia filled with spermatozoa, while 

 those of the other part became female, being transformed into sporan- 

 gia, developing many spores. He then described minutely the mode 

 in which the spermatozoa came into contact with the female cells 

 and fertihzed the spores. He also gave an account of the mode of 

 fecundation in the genus (Edogonium, 



"Having observed," the author remarks, "in the lower plants the 

 necessity of the material and immediate contact and union of sper- 

 matozoa and eggs or spores ; the want of a peculiar membrane around 

 the latter before impregnation ; the formation of this wall and the 

 multiplication of the developed cell as the immediate consequence of 

 fecundation, we may conclude that the same course of development 

 may also be followed in the reproduction of other organisms, — a con- 

 clusion which is entirely confirmed by the most recent observations 

 on the fecundation of animals." 



2. " On the Preparation of Sugar and Arrack from Palms in 

 Ceylon," by Alexander Smith, M.D. 



Three Palms yield sugar in Ceylon : Cocas nucifera, Borassus fia- 

 helliformis, and Caryota urens. From each of these the juice of the 

 flowering-stalk is collected, and from it sugar is regularly prepared ; 

 but it is from the Borassus that almost all the palm sugar is obtained. 

 It is from the sugar of the Cocas that arrack is made in Ceylon. 



3. "On the occurrence of Scalariform Tissue in the Devonian 

 Strata of the South of Ireland," by Robert Harkness, F.G.S., Pro- 

 fessor of Geology, Queen's College, Cork. 



The author, after noticing the occurrence of Cyclopteris hibernica 

 in the neighbourhood of Cork, remarked that in some of the higher 

 beds of the Devonians of the South of Ireland there had been found 

 great quantities of drifted vegetable matter in the form of more or 

 less perfect stems of trees, exhibiting in their interior a fibrous char- 

 coal-like substance, which when examined by the microscope presented 

 evident scalariform tissue, showing that the plants belonged to the 

 Fern alliance. 



4. " Notice of some additions to the Cryptogamic Flora of Edin- 

 burgh," by Mr. W. Nichol. 



The author remarked that the presence of such plants as Leskia 

 suhrufay Trichastomum flexicaulCi Anoectangium campactunif En- 

 calypta ciliata, Tortula tortuosaf Bryum Zieriij and Blindia acuta, 



