134 VIGNETTES FROM INVISIBLE LIFE. 



between them is greater. Their function is a 

 puzzle as yet to the naturalist, though, doubtless, 

 such prominent objects serve an important purpose 

 in the economy of their possessors. The upper 

 membrane over the head is also dotted over with 

 similar, but much smaller, bodies, shining out with 

 opaline tints. 



The ordinary method of viewing those creatures 

 is by means of light reflected by a mirror from 

 below the stage of the microscope through a para- 

 boloid, or spot lens, thus showing the object in a 

 soft, delicate light on a dark ground, very charming 

 and agreeable. There is, however, another plan, 

 concerning which a celebrated authority on this 

 subject recently wrote to me thus (speaking of 

 the Megalotroclia, some specimens of which I 

 had sent him) : " Have you treated it at night as 

 an opaque object, condensing a very bright light 

 from above on the group ? It is such a charming 

 object seen thus. The brilliant white spots, deli- 

 cate blue stomach, brilliant ruby spots on the sides 

 and elsewhere, and yellowish head, mastax, &c., 

 make an assemblage of colours rarely seen in a 

 Rotifer." 



