li'.IS SUMMARY OF CURRENT RESEARCHES RELATING TO 



In the ( 'yanophyceai there is uo nucleus, nor any structure which 

 resembles a nucleus. Two zones can be made out in the living cell, 

 one central, uncolourccl, the other peripheral, holding the pigment. 

 There is no evidence of the presence of a special chromatophore, the 

 pigment being dissolved in a fluid. There are two types of granule, 

 chiefly found respectively in the central body and in the peripheral 

 layer. The beterocyst is a degenerated cell, in which distinction between 

 the central and peripheral parts is lost. Division of the cell is direct. 



In no form of Beggialoa is there any specialised chromatin-holding 

 structure in the shape of a nuclus of any kind. There is no differentia- 

 tion of the cytoplasm into a central body and a peripheral layer. The 

 droplets of sulphur are contained in the central portion. 



In Saccharomyces the cytoplasm is usually finely reticulated, and 

 contains one or more vacuoles. In addition to the chromatin-likc 

 substance diffused throughout the nrotoplasm, there is usually a more or 

 less homogeneous spherical body in tlic cell, the "corpuscle," "nucleus," 

 "nucleole," and " nuclein body" of various observers, which stains 

 specially with hematoxylin, but is not either a nucleus or a nucleole. 

 There may be several in a cell or they may be entirely wanting. The 

 corpuscle divides when budding begins; but the division is purely 

 mechanical, and is not essential to the formation of the bud. In cells 

 of S. Luchvigit there are occasionally structures closely resembling a 

 nuclear organ ; they are composed of vacuolised chromatin. 



Reserve Carbohydrates of Thallophytes. * — In the Myxomycetes, 

 according to M. G. Clautrian, the most abundant carbohydrate is 

 glycogen, which usually occurs in the plasmodes in a half-dissolved con- 

 dition, less often as amorphous granules ; the spores contain only oily 

 substances. The Euflagellata, whether green or colourless, contain para- 

 mylon in the cytoplasm, not in the chromatophores. The Peridiniea) 

 contain drops of oil and true starch ; their membrane gives the reactions 

 of cellulose. The ( 'yanophycete often give with iodine a reaction re- 

 sembling that of glycogen. The presence of glycogen in the bacteria 

 has been rendered probable by Errera ; their membrane gives in many 

 cases amyloid reactions. In the green algse starch plays the most 

 important part. The composition of the brown algae has been but little 

 investigate J. In many red algae there is a carbohydrate closely allied 

 to starch. Fungi contain abundance of glycogen and oily substances, 

 besides various forms of sugar, glucose, levulose, trehalose, and 

 mannite. 



Influence of Chemical Agents on the Growth of Algae and 

 Fungi, j — N. Ono publishes the results of a large number of experiments 

 on the effect on Algae and Fungi of a number of different chemical salts, 

 accompanied by a series of tables. Extremely dilute solutions of some 

 poisonous salts promote the growth of the lower Algae ; among these arc 

 zinc sulphate, ferric sulphate, cupric sulphate, and iron arsenite. It is 

 the power of multiplication, not the size of the individual, that is favour- 

 ably affected. A smaller quantity of the mineral salt is more injurious 



* Misc. biul. ded. an Prof. A. Giard, p. 114, Paris, 1899. See Bot. Centralbl, 

 Ixxxiii. (1900) p. 159. 



f Journ. Coll. Sci. Imp. Univ. Tokyo, xiii. (1900) pp. 141-SG (1 pi.) (German). 



