566 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



carpus Mertensii (Tilopteris Mertensii, Kiitz) propagation 

 does not take place as in true Ectocarpi by zoospores, but by 

 large inactive spores. The antheridia are similarly situated 

 with the spores, and produce spermatozoids like those of Fuel. 

 The spores, however, like those of Gwtleria, germinate without 

 the access of the spermatozoids. In Dictyota, Dictyopteris, 

 Taonia, and Padina, he finds inactive spores ; while Aspe- 

 roccus and its allies are propagated by zoospores. He 

 describes and figures the antheridia of Dictyota dichotoma, 

 and shows the necessity of considerable reformation in the 

 classification of the Melanosperms in consequence of the 

 diversity of the reproductive organs. 



Page 319. — Tulasne has stated his opinion, in his memoir on 

 ITredinece, Ann. d. Sc. Nat., s^r. 4, vol. 2, p. 77, that the 

 greater part of the Uredines are merely stylospores of Puc- 

 cinia, Triphragmium, &c. His account of the genus Cro- 

 nartium, which grows on the leaves of Pwonia, Asclepias 

 Vincetoxicum, &c., is curious. It consists of a little cellular 

 sac, perforated by a column arising from its centre. This is 

 surrounded at the base by stylospores, which are capable of 

 germination. The cells of the column itself also germinate 

 and produce minute globose spores, which in their turn germi- 

 nate. The column, therefore, consists of an aggregation of 

 spores germinating in situ, and not, as has commonly been 

 supposed, of a peridium inclosing spores. 



Page 467. — A remarkable instance of anomalyin the geogra- 

 phical distribution of mosses is afforded by the species which 



Nemalion, Hypnea, Cruoria, Peyssonelia, Melohesia, Orcicilaria, Nito- 

 phyllum, Delesseria, Spermothamnion (Callithamiiion Turneri), Bornetia 

 (GrifBtlisia secundiflora), Wrangelia, Chylodadia, Laurencia, Bonne- 

 maisonia, Alsidium, Rhodomela, and Polysiphonia. Derb& and Solier 

 have observed them, in addition, in Rytiphlaa. It will be observed 

 that Porphyra and Bangia are placed amongst Rhodosperms byThuret, 

 which they resemble in the nature of their antheridia. Still more 

 recently Derbes has detected antheridia in a new genus, Ricardia, allied 

 to Dumontia, and in Taonia, after the fashion of those of Dictyota^ 

 (Ann. d, Sc, Nat., Oct. 1856.) 



