BACILLARIA. 411 



Schriften v. Goze, p. 1. fab. 1. 8., 1782; Pinddyr Nye 

 Samling af Dansk Vidensk. Sallsk. Skrift. 11. p. 277. 

 Vibrio paxillifer Miiller, Animalc. Infus. p. 54. t. 7. 

 f. 3. 7., 1786. Bacillaria paradoxa Gmelin, Linnaei 

 Syst. Nat. ed. xiii. vol. vi. 1788. Vibrio paxillifer La- 

 mark, Systeme des Anim. sans Vert. 1815. Bacillaria 

 palea Nitzsch, in part, Beitrage zur Infusorienkunde, 

 1817; Encyclopadie v. Ersch u. Gruber, 1821. Bacil- 

 laria paradoxa Bory de Saint Vincent, Diet. Classique, 

 1822. B. Mulleri Bory, Encyc. Meth. 1824. Oscil- 

 laria paxillifera Schrank, Nov. Act. Nat. Cur. xi. 2. 

 p. 534. 539. Bacillaria Mulleri Turpin, Diet, des Sc. 

 Natur. Vegetaux Acotyledones, 1828. Bacillaria para- 

 doxa, Abhandl. der Akademie d. Wissenseh. zu Berlin, 

 1831, p. 83. ; 1833, p. 319. ; Ehr. Infus. p. 196. t. xv. 

 f. 1. 



This is the most singular of all the Diatomaceoe, and the 

 most protean in the forms which it assumes ; the variety of 

 which results from the power which the frustules undoubt- 

 edly possess of gliding one upon the other. Sometimes 

 the margins of the frustules correspond in position with 

 each other, and then an elongated lamina is formed similar 

 to that of the Fragilarice. At others the frustules are drawn 

 out from each other by two and three together, and the 

 margins are rendered uneven ; and again at others, each frus- 

 tule composing a frond is drawn out, so that it adheres but 

 by a very small portion of its length to the frustule or frus- 

 tules, one on each side, with which it is connected. Now 

 this disposition of the frustules could only be effected by the 

 possession of a power of motion the one upon the other. 



Ehrenberg in his definition of this species makes use of 

 the following phrase, ( f baccillis singulis alacriter mobilibus ; " 

 and, again, in the definition given in French, " les baguettes 

 vivement mobiles." Now it ought not, I apprehend, to be 

 imagined, as the words quoted would lead us to suppose, that 

 the frustules possess each and individually a power of loco- 

 motion centered in themselves, but merely that they are so 



