ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 441 



exhibits ordinary sexual reproduction. The zoospores and the gametes 

 in this organism possess a locomotor apparatus much more complicated 

 than has hitherto been described. It consists of two flagella situated 

 anteriorly ; a blepharoplast or insertion-nodule of the flagella, resulting 

 from a thickening of the ectoplasm ; a thread which starts from the 

 blepharoplast and is placed by the side of the nucleus, the rhizoplast ; 

 and a small nodule at the point of contact of the rhizoplast with the 

 nuclear membrane, the condyle. The sperm atozoid exactly reproduces 

 during its formation these various processes in the zoospore, from which 

 it is unquestionably derived. The centrosome does not play the part 

 that has been attributed to it in spermatogenesis. It is only in the 

 process of karyokiuesis that it can be regarded as the dynamic centre. 



Muscineae. 



Cave Mosses.* — L. Geneau de Lamarliere and J. Mareu have in- 

 vestigated the specialities of structure of the mosses found in caves in 

 •certain districts of France. They agree in general with those of species 

 which grow in dense shade and in cold or damp places, having in some 

 instances a distinct boreal character. No special species is described. 

 The Hepatic® appear, on the whole, to be less affected by the absence 

 of light than the Musci. 



Fossil Moss.t — I n a locality in Saxony (geological formation not 

 stated) A. Geheeb finds the remains of a moss indistinguishable from 

 Hypnum fluitans, which he names H. fluitans forma fossilis. 



Rhizoid-rudiments on the Ventral Scales of Marchantiaceae.} — ■ 

 C. Warnstorf describes, in the case of several species of Marchantiaceae, 

 a peculiarity resembling that found by Correns § in some Musci, viz. the 

 cajmcity of certain cells to form rhizoids or protonema. In the Marchan- 

 tiacese (Marchantia polymorpha, Fegatella eonica, Targionia hypophylla, 

 &c), these conical rhizoids occur on the ventral scales, as they do also 

 in Corsinia marchantioides ; in Calypogeia trichomanis they are found 

 on the scales of the male branches. 



Algee. 



Galls on Algae. || — Dr. A. Trotter enumerates the recorded cases of 

 galls found on seaweeds and freshwater algae. Of zoucecidia, in addition 

 to the well-known parasitism of Notommata Werneclci on Vaucheria, he 

 mentions galls produced by Tylenchus fucicola on Ascophyllum nodosum, 

 and by Harpacticus chelifer on Rhodymenia palmata. Among phyto- 

 cecidia; — bacteria produce galls in a number of algae, both marine and 

 freshwater. The fungi which produce galls in algae appear to be confined 

 to the Chytridiaceae. Of algae producing galls on algae several instances 

 are mentioned: — Strcblonemopsis irritans on Cystoseira opuntioides; 

 Ectocarpus valiantei on Cystoseira ericoides. A list is further given of 

 the species of algae which produce galls on Phanerogamia and on 



* Comptes llendus, exxxii. (1901) pp. 921-3. 



t Beih. z. Bot. Centralbl., x. (1901) pp. 125-7. 



t Hedwigia, xl. (1901) pp. 132-5 (5 figs.). § Cf. this Journal, 1899, p. 5G4. 



|| La Nuovu Notarisia, xii. (1901) pp. 7-24. 



