DELESSERIA. 



[ 191 ] 



DEMATIEI. 



Fig. 164. 



tueuts of the cell-contents. It is curious 

 that portions of the flesh and other proteine- 

 components of one animal, when kept in the 

 peritoneal cavity of another living animal, 

 will undergo fatty degeneration. The for- 

 mation of adipocire is probably an instance 

 of post-mortem fatty degeneration. See Fat. 



BiBL. Yirchow, Archiv, 184/. i. p. 94 ; 

 Bm'dach, ibid. vi. p. 103 ; Wedl, Gi^widzuge d. 

 Path. Hist.; Forster, Handb. d. Spec. Path. 

 Jnat. ; Wagner, Nadir, d. Ges. d. Wiss. z. 

 Gottingen, Ma}^, 1851 {Chem. Gaz. ix. p. 

 309). 



DELESSERIA, Lamx.— A genus of De- 

 lesseriaceae (Florideous Algse), consisting of 

 sea-weeds with a flat, membranaceous, rose- 

 coloured frond, having a percurrent midrib, 

 growing on rocks or on other larger Algse, 

 mostly from 2 to 8 inches high. Six species 

 are described as British, most of them com- 

 mon. The leaf-hke lobes of the frond arise 

 from a kind of stalk, or from the midribs of 

 older lobes. The tex- 

 ture is densely paren- 

 chymatous throughout. 

 D. sanguinea ripens its 

 fruit in the winter, and 

 then the membranous 

 part of the fronds de- 

 cays, leaving the micbibs 

 clothed with tufts of the 

 sporophylls or leafy 

 lobes containing the te- 

 traspores (fig. 164), and 

 stalked coccidia con- 

 taining the spores. The 

 fructification is some- 

 what similar in D.alata, Delesseria sanguinea. 

 while in D. sinUOSa the Midribs of fronds in winter 



coccidiaareimmersedin ^"^"^"^ sporophylls. 

 the frond, and the tetra- ^^*- "^^• 



spores in cilia-like processes fringing its 

 margin ; and in D. Hypoglossum the coccidia 

 are seated on the midrib, and the tetraspores 

 arranged in longitudinal linear rows like sori 

 on each side of the midrib. 



BiBL. Harvev, Brit. Mar. Alg. p. 113. 

 pi. 15 A; Phyc.'^Brit. pis. 2. 26. 83. 151. 

 247. 259; Greville, .4?^. Bn^. pi. 72-/4, 76. 



DELESSERIACE.E.— A family of Flo- 

 rideae. Rosy or purplish-red, or blood-red 

 sea-weeds, with a leafy, or rarely filiform, 

 areolated, inarticulate frond, composed of 

 polygonal cells. Lobes of the frond deli- 

 cately membranous. Fructification double : 

 1. Conceptacles {coccidia) external, or half- 

 immersed, hemispherical, usually imperfo- 

 rate, containing beneath a membranous peri- 



carp a tuft of dichotomous filaments, whose 

 articulations are finally changed into spores. 

 2. Tetraspores in distinctly definite sori, 

 either scattered through the frond or placed 

 in proper fruit-lobes or sporophylls. 



Synopsis of the British Genera. 



I. Delesseria. Frond leafy, of definite 

 form, with a percurrent midrib. 



II. Nitophyllum. Frondleafy, of indefinite 

 form, without a midrib (sometimes traversed 

 by vague, vanishing nerves). 



III. Plocamium. Fro/i^/linear or filiform, 

 compressed, much branched, distichous; 

 ramuli pectinate, secund. 



BiBL. See the genera. 



DEMATIEL — AfamilyofHvphomycetous 

 Fungi, growing on the dry parts of plants, 

 and characterized by the mostly septate 

 spores being attached to rigid thick-walled 

 filaments, which are continuous or septate. 



Synopsis of British Genera. 



I. Cephalotrichum. Fertile filaments 

 stalk-like, erect, septate, terminating in a 

 globose capitule, formed by radiating forked 

 or ternate branches bearing globular spores 

 at their tips. 



II. Rhopalomyces. Fertile filaments erect, 

 continuous, simple, terminating in a globular 

 head of spores, which are seated on a cellular 

 capitule; the cells of this are hexangular, 

 with a cup-like depression in the middle, 

 and each with a wart-like apiculus in the 

 middle, bearing a spore. 



III. Sporocybe. Filaments rather fibrous, 

 subulate, capitate, bearing simple s])ores 

 conglobated into a terminal head. 



IV. (Edemium. Filaments rigid, erect, al- 

 most continuous, or annulated, bearing at 

 the sides globular masses of spores. 



V. Myxotrichum. Filaments erect, scarcely 

 septate, fertile branches crowned by globules 

 of heterogeneous conglutinated spores. 



VI. Helminthosporiiim. Filaments erect, 

 simple, septate ; spores transversely septate. 



VII. Bolacotricha. Filaments simple, uni- 

 formly articulate at the apex ; spores con- 

 glomerated, large, globular, shortly stalked, 

 contents distinctly granular. 



VIII. Triposporium. Filaments erect, sep- 

 tate, sterile branches solitary, more or less 

 spreading ; fertile branches shorter, bearing 

 at the tips solitary, stellate, mostly very 

 shortly stalked spores. 



IX. Helicosporium. Filaments erect, subu- 

 late, closely septate, continuous and dia- 

 phanous at the summit ; spores thread-like. 



