ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 275 



there is one chloroplast in each semi-cell, the differenb forms encountered 

 being variations of one simple type. Always there is a more or less 

 distinct axile plate parallel to the front face 5 of the semi-cell in the 

 central position, and from this there usually arise numbers of ridges or 

 plates which project towards the cell-wall in various directions. The 

 relative size of axis and ridges varies with different species. The 

 prominence of the ridges seems to depend on the thickness of the cell ; 

 in the more flattened cells of some species they are insignificant and may 

 under certain physiological conditions be altogether absent, but in the 

 thicker-celled species they are very large and may sometimes even be 

 branched. The ridges in the latter case constitute by far the more 

 important part of the chloropList, the axis often becoming very thin 

 and indefinite in form. With the increase in size and importance of the 

 ridges, the pyrenoids become more restricted in number and disposition, 

 occurring only in the more massive parts of the chloroplast. In most 

 species a tendency was noticed for the axis of the chloroplast to become 

 shortened in the apical lobe of the cell. This is more pronounced in the 

 thicker-celled species, in which the chloroplast may even tend to become 

 parietal in this region by reason of the absence of the axis. Sometimes 

 the shortening of the axis in the median region extends through the 

 whole length of the semi-cell, in which case two chloroplasts are present 

 instead of one. A. G. 



List of Desmidiacese collected during the Summer of 1913 in 

 the Government of Ufa. — A. J. Lobik ( Bull. Jard. Imp. Bot. Pierre 

 h Grand, 19U, 14, 259-76 ; see also Bot. CentralU., 1915, 128, 702). 

 Thirty-nine species were determined, some of which ditfered greatly 

 from the recognized type — Penium margaritaceum Breb. f. incoloratum 

 Lobik ; Closteriurn. siliqua W. & G. S. West var. wajus Lobik ; Euastrum 

 binale Ralfs f . intermedium Lobik ; Cosmarium Eichhri Lobik comb, 

 nov. f. vfense Lobik. The two species Euastrum binah Ehr. and 

 E. duhium Nag. are united under E. binale Ehr., as intermediate forms 

 were found which nullify the supposed distinguishing characters in size, 

 form, and structure. A comparison of the diagnoses of Cosmarium suh- 

 broomei and of the var. 7-etusum of Eichler and Gutwinsk shows that the 

 variety is wrongly placed under C. subbroomei. They differ in the form 

 of the angles of the semi-cells, and in the outline of the lateral walls. 

 The variety is here raised to specific rank as C. Eichler i, the name i-etiisum 

 liaving been already used for another species. E. S. G. 



Epiphyllic Ulothrix. — A. Eckley Lechmere {Naturiv. Zeitschr. 

 Forst-und Lnndw., 1915, 13, 30-30, 2 pis. ; see also Bot. Gentralbl., 

 1915, 128, 702). The result of an investigation of the dark green 

 growth frequently found covering pine-needles. It is formed of a species 

 of Ulothrix, of which the author here describes the morphology, growth 

 in nutritive solutions, and germination of the akinetuspores. Germina- 

 tion may be either direct, or indirect by means of reproductive akinetse 

 or by a Palmella stage. No mobile spores are formed. The systematic 

 position of the alga was difficult to establish, owing to want of unanimity 

 among authors as to distinguishing characters — e.g. form of the chloro- 



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