EHIZOPODA. 5 



(12.) Granting the accuracy of the above view, it is obvious that, if 

 exactly acquainted with the structure and elaboration of the nervous 

 apparatus in any animal, we might to a great extent predicate the 

 most important points in its economy, and form a tolerably correct 

 estimate of its powers and general conformation. But, unfortunately, 

 such knowledge is not always at our disposal : in the lower forms of 

 the animal world especially, we are far from being able to avail our- 

 selves of such a guide ; and it will probably be long ere our improved 

 means of research permit us to apply to practice the views which 

 Physiology would lead us to adopt. It is, however, by no means our 

 intention in the present work to enter the arena of discussion relative to 

 the juxtaposition or precedence in the scale of animal existence which 

 ought to be assigned to any particular group as denned by modern 

 zoologists. The classification employed in the following pages is simply 

 adopted as being the most convenient for our present object ; we shall 

 therefore arrange our studies in accordance with the following sequence. 



CHAPTER II. 



PKOTOZOA*. 



(13.) EHIZOPODA f. On carefully examining the contents of a marine 

 aquarium, or a glass vessel casually filled with sea- water, the micro- 

 scopic observer will not unfrequently perceive, adherent to the sides, 

 numerous beings which, from their minute size and transparency, have 

 until a very recent period entirely escaped notice, although the part 

 they are destined to play in the economy of this world is by no means 

 unimportant. The body of one of these remarkable organisms (fig. 1, 1) 

 consists of a minute spherical vesicle, something resembling a globular 

 flask provided with a short narrow neck, filled with a fawn-coloured 

 glutinous substance containing numerous minute granules, and appa- 

 rently unprovided with any external appendages. On placing one of these 

 creatures, however, in a glass of sea-water (its native element), it is found 

 in the course of a few hours to have attached itself to the sides of the ves- 

 sel by means of numerous long ramified filaments of hyaline transparency, 

 which soon begin to reveal their office to be that of a locomotive appa- 



* Trpoiros, first; wov, animal. 



t Vide D'Orbigny, Diet. Univers. d'Hist. Nat. 1845, v., and Foraminiferes Fossiles, 

 1846 : Ehrenberg, Berlin Trans. 1838 and 1839, or Weaver's abstract, Ann. Nat. 

 Hist. 1841, vii. pp. 296, 374: Dujardin, Ann. Sc. Nat. 1835, iv. & v. : Clark, Ann. 

 Nat. Hist. 1849, iii. 380; 1850, v. 161 : Williamson, Trans. Micr. Soc. ii. and Micr. 

 Journal, i. : Carpenter, Trans. Geol. Soc. 1849, and Phil. Trans. 1856 : Carter, Ann. 

 Nat. Hist. 1852, x. 



