ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 359 



folia raraea distiche coruplanata, asymrnetrica, ovata, raptim in acumen 

 plus minus flexuosum producta, ecostata ; rete densiusculo, cellulis 

 basilaribus elongate rectangulis, mediis elongatis lineari-subrhombeis, 

 superioribus oblongo-rhombeis ; folia stipukeformia multo minora, 

 deltoideo-lanceolata, sensim acuminata, cuspidata, enervia, e cellulis 

 nniformibus lineari-subrhombe reticulata. 



Hermaphrodite Gametophore in Preissia commutata.* — Miss Anne 

 B. Townsend records an example of this representative of the Marchan- 

 tiacese in whicb, instead of tbe gametophore bearing one kind only of 

 sexual organs, it bears both kinds. It appears to be primarily an arche- 

 goniophore modified to adapt it to its peculiar conditions. 



Algae. 



Movements in Bornetia secundiflora.f — Sig. A. Preda has noticed 

 that when this seaweed is immersed in fresh water, an apparently 

 spontaneous movement sets up in the frond after a few seconds, the 

 branches suddenly contracting spasmodically. These movements 

 continue until the thallus has completely lost its turgidity, and are 

 accompanied by a strong crackling, due to the successive rupture of the 

 cells, which expel their contents to a considerable distance. The author 

 attributes the phenomenon to a violent endosmose. 



Fertilisation of Batrachospermum.J — Herr W. J. V. Osterhaut has 

 followed out this process in the case of B. Boryanum. The " spermatia " 

 (pollinoids), each of which contains a single nucleus, attach themselves 

 to the trichogyne near its tip. At the point of contact the cell-wall of 

 both trichogyne and pollinoid are completely absorbed, and the nucleus 

 of the latter passes into the trichophore ; and the author has been able 

 actually to observe its fusion with the ovum-nucleus. The formation of 

 the gonimoblasts and spores was also followed out. The author does 

 not confirm the statement of Schmidle § that each pollinoid contains 

 two nuclei. 



Thorea.|| — Mr. G. G. Hedgcock and Mr. A. A. Hunter describe the 

 structure of this alga, their account agreeing in all essential points with 

 that of Schmidle. They find the three distinct stages : — (1) The pro- 

 thallium stage, consisting of more or less branched cellular fibres, which 

 <levelope directly from the spores ; in this stage neither spores nor 

 tetraspores were found ; (2) The chantransia stage, developing directly 

 from the first ; in this stage non-sexual spores are produced ; (3) The 

 branching plant, constituting the most highly developed form, in which 

 carpogones are formed in addition to the other organs of propagation. 



Phaeocystis globosa sp- n.f — Herr A. Scherffel describes this new 

 species obtained in plankton from Heligoland. The colour of the 

 chromatophores, the arrangement of the cell-contents, the presence of 

 leucosin, the formation of the primary and secondary flagella in the 

 swarming stage, and the structure of the colonies, indicate a close 



* Pot. Gazette, xxxviii. (1899) pp. 3G0-2 (1 fig.). 



t Bull. Soc. Bol. Ital., 1898, pp. 230-2. 



X Flora, lxxxvii. (1900) pp. 109-15 (1 pi.). § Cf. Urn Journal, 1899, p. 628. 



11 Bot. Gazette, xxxviii. (1899) pp. 425-9 (1 pi.). 



«j Ber. Deutsch. Bot. Geaell., xvii. (1899) pp. 317-8. 



