THE BEGINNINGS OF LIFE, 449 



vesicules parifissees adherentes entre elles, va jusqu'a 

 la 3 , 4 e , 5 e , 6 e division ces vesicules s'arrangent sur 

 un meme plan , celles du contour poussent des comes 

 et pre'sentent les jolies formes des Micrasterias *.' 

 Whilst the transformation into one or other of the 

 varieties of Arthrodesmus (g, b) seems to occur still 

 more frequently. Dr. Gros writes : c Les Arthrodesmus 

 qui ne sont que le 3 degre de parifissure prenaient des 

 formes d'autant plus exigues que les utricules, d'ou ils 

 descendait, etaient plus petits 2 .' One of the con- 

 ditions under which Euglense are prone to undergo 

 transformation into Pediastrese has also been definitely 

 ascertained. Dr. Gros observed that when Euglenae' 

 were sown upon a small patch of damp earth some of 

 them generally underwent this kind of metamorphosis, 

 although others passed through different changes, so as 

 to become converted either into Diatoms or into the 

 organisms of which we are now about to speak 3 . 



9. Transformation into Conferva. Not only may the 

 ultimate products of repeated fissions of Euglenae be- 

 come converted into small Confervae, as we have already 

 stated (p. 443, note O^ ^ ut occasionally an Euglena, 

 without such preliminary processes of fission, begins to 

 vegetate so as to produce a much larger Algal filament 



1 See loc. cit., p. 311, and PL K, fig. 25. 



2 PL P, fig. 20-23. These transformations of Euglenge into different 

 kinds of Pediastreae are also referred to by Dr. Gros at pp. 303, 309, 318, 

 and 452. 



3 See p. 453. 



VOL. II. G g 



