272 



THE MICROSCOPE. 



The shell may be hyaline and tubuliferous, or opaque 

 and homogeneous, or arenaceous, i. e. made up of siliceous 

 or other particles cemented with shell-material. 



v.Forammifera, indeed, are to be compared with the 

 other lowest orders of animals and of plants in the study of 



Fig. 165. 



1, Section of Faujasina: a a, radiating interseptal canals; b, their internal 

 bifurcations ; c, a transverse branch ; d, tubular wall of the chambers. 2, 

 Rosalind ornata, with its pseudopodia protruded. 



their specific relations. In these several low forms of 

 creatures we have comparatively few species, but extremely 

 numerous individuals, with an enormous range of variety. 

 In the higher orders of plants and animals the specific 

 forms are more definite, there being a more complex 

 organization, harmonizing with the special habits of each 

 creature ; and the individuals of each species are less 

 numerous than is the case in the Protozoans and Pro- 

 tophytes. 



" These low animals, the Foraminifera, having great 

 simplicity of structure, more easily adapt themselves to 

 varying external conditions than the more complex and 

 specialized higher animals." 



In the deep-sea soundings, portions of the beautiful 

 Diatoms, lately figured and described by Professor W. 



April, 1857. 



