ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 405 



The structure and mode of formation of the spores are described 

 in detail ; and it is shown that in the anthonimorphous type (Hysterium 

 Smilacu, Stictis versicolor, &c.) the mother-membrane takes no part 

 in the abstriction of the spores ; but that a new membrane is formed, 

 the old one becoming gelatinized. The formation of the multi- 

 cellular filiform spores of Hahrostictis rubra, Sticlis nivea, &c., is also 

 described in detail. 



The germination is described of the spores of Lophium loeviusculum. 

 After the destruction of the asci, the spores remain for a shorter or 

 longer time in the fructification, where they germinate ; passing over 

 ultimately into a chroolepis-like gonidema, and not, as would be the 

 case if Schwendener's hypothesis were true, developing into a fungus. 



The two different forms of ascus correspond to the two different 

 forms of spore. When the ascus has a double wall, the inner layer 

 of which ultimately gelatinizes, then the spore has only a single 

 membrane ; while when the ascus has only a single wall, the spores 

 have a double membrane, the outer layer of which gelatinizes. 



Algee. 



Chromatophores of Algse.* — By the term Chromatophores, F. 

 Schmitz designates chlorophyll-bodies, coloured (not green) pigments, 

 and other analogous colourless bodies. With the exception of the 

 Phycochromacese, all algse possess chromatophores — the colour never 

 being due to a green cell-sap — though they are often difficult to detect 

 from the delicacy of their envelope or from their being concealed by 

 other cell-contents. 



The form of the chromatophores is very various, but remains 

 constant for the same species, and furnishes also distinguishing 

 characters for the genera. Their arrangement is either irregular or 

 more or less regular. In the latter case they may form straight rows, 

 as in Characefe ; beautiful nets, as in the medullary cells of the stem 

 of Laurencia, &c. ; or curves, as in many Floridese, &c. &c. They are 

 never in direct contact with the cell-wall or cell-sap, but are always 

 surrounded by a thin, often scarcely perceptible layer of protoplasm. 



The living chromatophore has, as a rule, a perfectly homogeneous 

 appearance; but those of Spircgyra majuscula exhibit, under high 

 powers, an evident punctation. A similar structure is often visible 

 after fixation with picric acid ; in other cases they appear, after hard- 

 ening, to consist of a uniformly dense and very opaque substance. 

 The wide-meshed reticulate appearance which they assume after 

 treatment with acids and other reagents is the result of dis- 

 organization. 



The colourless ground-substance of the chromatophores agrees 

 altogether in its reactions with the cell-protoplasm, and is simply a 

 portion of it adapted for special functions. Sometimes it constitutes 

 the whole chromatophore, which is then colourless ; but this, which 

 is very frequent with the higher plants, occurs but rarely with algje, 



* Schmitz, F., Die Chromatophoreu den Algen, 180 pp., 1 pi., Boun, 1882. 

 See Bot. Centialbl., xiii, (1883) pp. 289-94. 



