PROGRESS OF MICROSCOPICAL SCIENCE. 139 



more densely branched ones appear furcate. The author says that 

 the fructification is of two kinds : 1st, Tufts of branched moniliform 

 cells, of a darker colour than the cells of the frond, each cell siu- 

 rounded by a hyaline border ; these tufts are situated on the rachis 

 of the plumules and pinn?e, but are never formed from the terminal 

 branchlets. 2nd, Elliptical cells, two or three in number, forming a 

 whorl round, and semi-immersed in, the upper part of the articulations 

 of the plumules. Both the tufts and the whorls of cells appear to 

 contain graniilar matter, but show no appearance of being tetraspores. 

 This very remarkable plant bears some resemblance to Seriospora 

 Grifiithsiana, but differs from it in its want of gloss, different colour, 

 in the moniliform cells never being terminal, and not foi-med from 

 the branchlets, but an independent growth on the rachis, and in the 

 presence of the whorled elliptical cells. It is interesting to find that 

 there is a specimen in Mrs. Griffiths' collection of Algfe belonging to 

 the Linnean Society, which was gathered at Salcombe, in 1840, and 

 which presents the same character of tufted cells, &c. This specimen 

 is marked " Seirospora ? " 



The second species is Nitophjllum thysanorMzans, N.S. — JiVcro- 

 scopical Structure : Cells polygonal, becoming smaller and quadrate at 

 the margin of the frond ; the cellular processes are composed of large 

 elongate polygonal cells, which become smaller and very dense toward 

 the point from which the roots arise. A network of minute veins 

 traverses the whole of the frond, and is especially noticeable in the 

 ultimate segments, the veins being formed of a single row of narrow, 

 somewhat cylindi-ical cells. Tetraspores distinctly tripartite, col- 

 lected into definite rounded sori in the apices of the ultimate seg- 

 ments. Capsular fructification not yet met with. Habitat : Thrown 

 up on a mud-bank at Torpoint, and at Moimt Edge umbo, near Ply- 

 mouth. Perennial? This interesting little plant has probably been 

 overlooked for many years as a variety of Uliodymenia bifida, under 

 which name I have several times received it, and have also seen it 

 among the Algae collected by the late Dr. Cocks, and now in the pos- 

 session of the Linnean Society. This mistake has most likely arisen 

 from the similarity of its branching to that of JR. bifida, and perhaps 

 also from the rare occurrence of its tetraspores. From B. bifida, how- 

 ever, and from B. crisfata, which it also resembles, it is abimdantly 

 distinguished by its definite sori, and tripartite tetraspores. From 

 Nitophyllum punctatum, to the narrow forms of which there is a close 

 resemblance in colour and general appearance, it is separated by 

 the tetraspores forming sori in the apices of the frond only, and by its 

 fimbriate margin. 



Hie Gonidia of Lichens. — In the ' Annales des Sciences Naturelles ' 

 (Botanique), vol. xvii., M. E. Bornet records a series of observations 

 on the gonidia of lichens, made on species belonging to sixty different 

 genera. The conclusion to which his examination has led the wi-iter 

 is that the relations of the hypha to the gonidia of lichens are of such 

 a nature that they exclude the possibility of one of these organs being 

 produced from the other ; the theory of parasitism being the only one 

 which can give a satisfactory explanation of these relations. He 



