KX P LA NATION O F T II E P L A T E S. 259 



Fig. 15. Cosmaritim Hroomei, Thw. Front view, mairiiilinl 4GO diameters. 

 Fig. lt>. Cwmuriinn cnmmiissurale, lln li. Front view, magnified 7 f>0 diameters. 

 Fig. IT. Xuiit/itiltuni annul um. Ureli. Front view, luagniQed 2CO diameters. 



PLATE XIV. 



Fig. 1. A sterile cell of Rhynchonema clongatum, Wood, magnified 450 diameters. 

 Fig. 1 a. Portiuu of a liluuieiit coutaiuing a fertile cull, with tin- sport) nearly matured, amplified 

 450 diameters. 



Fig. 2. A filament of Jlhym-honema pulchellum, Wood, containing both fertile and sterile cells, 

 magnified 2(10 diameters. 



Fig. 3. The ripened spore of Spirogyra protecla, Wood, magnified 450 diameters. 



Fig. 3 a. Outline of conjugating filaments, and figure of a sterile filament, enlarged 250 diameters. 



Fig. 4. Sterile cells of Spirogyra longala (Vauch.), magnified 250 diameters. 

 Fig. 4 a. Fertile filaments, magnified 2GO diameters. 



Fig. 5. A filament of Aphanocheete repen,Wood, which has lost its cilia, magnified 4GO diameters. 



Fig. (i. A fertile branch of Drapamaldia Billingsii, Wood, showing the chains of spores, mag- 

 nified 4i;o diameters. 



PLATE XV. 



Fig. 1. Portion of a filament of Spirogyra majugcula, Ktz., containing cells with mature spores 

 and others just commencing the process of conjugation. 



Fig. 2. A portion of a sterile filament of Spirogyra diluta, Wood, magnified 125 diameters, also 

 the outline of a pair of conjugating filaments of the same amplification. 



Fig. 2 b. Conjugating filaments of Spirogyra diluta, Wood, magnified 125 diameters. 



!'_'. 3 a. Portion of a sterile filament of Spirogyra setiformis (lloth) Ktz., magnified 125 

 diameters. 



Fig. 3 b. Conjugating filaments of the same species, similarly amplified. 



Fig. 4 a. Cells of Spirogyra crassa, Ktz., preparing for conjugation. 



Fig. 4 c. Conjugating cells of the same plant in the first stage of nnion. 



Fig. 4 b. Conjugating cells containing nearly matured zygosjwres, enlarged 125 diameters. 



Fig. 5. Filaments of JHesocarpwt scalaris, Ilassall, commencing the process of conjugation, mag- 

 nified 125 diameters. 



Fig. 6. Sterile cells of Spirogyra insignia (Ilassall) Ktz. 

 Fig. 6 6. Conjugating filaments of the same species. 



Fig. 7. Conjugating filaments of Spirogyra parvispora, Wood, containing nearly matured 

 spores, magnified 125 diameters. 



Fig. 8. Portion of an ordinary sterile filament of Zygnema insigne (Ilassall) Ktz. 

 Fig. 8 a. Fertile filaments of the same, magnified 250 diameters. 



Fig. 8 6. Sterile filament in which multiplication of the species is taking place by the separation 

 of the cells, magnified 260 diameters. 



PLATE XVI. 



Fig. 1 o. Cells of Sirogonium relroversum, Wood, just commencing the process of conjugation. 



Fig. 1 6. Sterile cells. 



Figs. 1 d and 1 e. Outlines of fertile cells ; all of these figures are magnified 260 diameters. 



