684 SUMMARY OF CUEEENT EESEAECHES EELATING TO 



a septum as the carpogonium. The cells with which the trichogyne 

 or tubes which proceed from it, conjugate, the auxiliary cells, are of 

 two kinds : — fertile, those which, after conjugation with the connect- 

 ing filaments which proceed from the carpogonium, form cystocarps ; 

 and sterile, which do not bring about this result. These sterile 

 auxiliary cells occur in Dudresnaya, Calosiphonia, and Nemastoma, 

 but not in the other genera. When present they are always in the 

 immediate vicinity of the carpogonium, while the fertile cells are 

 often at a greater distance from it. In the Halymeniese (Halymenia, 

 Grateloupia, and Cryptonemia) the auxiliary cell is homologous 

 morphologically with the carpogonium, and is surrounded by a similar 

 group of investing filaments. Each fertilized carpogonium may give 

 birth to a large number of auxiliary cells for the purpose of forming 

 a cystocarp ; and this is especially the case in the Halymenieaa and 

 in Nemastoma. 



The number of species described is twenty, among which are two 

 new ones, Gymnophlcea pusilla and Calosiphonia neapolitana. 



Sieve-hyphae in Algae.* — Dr. N. Wille states that in the stipes 

 of certain Laminariaceee, a portion of the hyphse running through it 

 in a longitudinal direction have long narrow cell-cavities, and that 

 the transverse walls of these cells are perforated in the same way as 

 those of the sieve-tubes of Phanerogams. These sieve-hyphse are 

 also connected with one another transversely by short branched hyphge, 

 thus causing a complex system of communication of the sieve-hyphse 

 with one another, and between these and the assimilating system. 

 The sieve-hyphaB occur also as a middle lamella between the two 

 assimilating layers in the leaves of Laminaria ; and evidently per- 

 form a very important function in the conveyance of nutriment from 

 one part of the plant to another. 



These sieve-hyphae were observed in Laminaria digitata, Clustoni 

 and saccharina. A somewhat similar structure occurs in the leaves of 

 Fucacese ; and in Chorda filum, a similar though less developed system ; 

 also in Chordaria flag elli for mis. In the Floridese conducting hyphse 

 of various kinds are also found. In Cystoclonium purpurascens the 

 entire conducting system is surrounded by a protecting ring of large 

 thick-walled cells. 



Algse of Bohemia. I — Dr. A. Hansgirg enumerates the fresh- 

 water algae found in Bohemia, which have not previously been 

 observed, and describes the following new species : — Micrococcus 

 ochraceus, Gloeocapsa salina, Nostoc halophilum. 



Pelagic Algae. I — Dr. E. F. Solla gives a list of twenty-three 

 species of marine algte (besides four unnamed) obtained from the 

 island of Lampedusa, and eighteen from the island of Linosa, both off 

 the coast of Sicily. They belong to the families Porphyraceae, 

 Ceramiaceee, Spyridiaceae, EhodymenaceaB, Hypnaeacea3, Gelidiaceae, 



* Ber. Deutsch. Bot. Gesell., iii. (1885) pp. 29-31 (1 pi.). 

 t Oesterr. Bot. Zeitschr., xxxv. (1885) pp. 113-7, 161-6. 

 t Ibid., pp. 48-53. 



