6 EXPLANATION OF THE PLATES. 



with the endochrome slightly condensed. Fig. 22. The 

 extremity has become clavate, and the endochrome con- 

 siderably condensed, though still continuous with that of 

 the remainder of the filament. Fig. 23. A diaphragm is 

 formed between the endochrome contained in the clavate 

 extremity of the filament and that of the filament itself. 

 Fig. 24. The spore is completely formed, and surrounded 

 by a transparent border. Fig. 25. The spore is repre- 

 sented in the act of escaping from the ruptured extremity 

 of the filaments. Fig. 26. The extremity of the filament 

 subsequent to the escape of the spore. Fig. 27. Spore 

 after its emission : it is enveloped in a granular epispore : 

 the cilia3 are invisible ; the colourless extremity is always in 

 advance. Fig. 28. The spore, the movements of which 

 have become retarded. Fig. 29. A spore, the movements 

 of which have been suddenly arrested in iodine water. The 

 ciliae are distinguished on the margin short and fine, which 

 are the organs of locomotion. Fig. 30. Spore treated with 

 iodine and dried bet \veen two plates of glass ; the cilia) 

 have become much more clear, and appear longer by reason 

 of the retraction of the epispore. Fig. 31. Spore pre- 

 paring to germinate ; it has become globular ; the colour- 

 less portion is no longer to be distinguished, and the epispore 

 has disappeared. Figs. 32, 33. Germination. The extre- 

 mities of the newly formed filaments are colourless. 



PLATE III. 



Fig. 1 . Vaucheria geminata. Fig. 2. Vaucheria racemosa. 



PLATE IV. 



Fig. 1. Vaucheria dichotoma. Fig. 2. Vaucheria sessilis. 

 Fig. 3. Vaucheria Dillwynii. 



PLATE V. 



Fig. 1. Vaucheria hamata. Fig. 2. Vaucheria terrestris. 

 Fig. 3. Vaucheria ovoidea. 



