166 THE AMERICAN MONTHLY [May 



very few people who know how it should be carried out. 

 The cornea must be flattened, not left in the g-lobular con- 

 dition of life. The simplest way to exhibit the effect is to 

 cut a cross out of brown paper, about %" long-, place this 

 on the mirror of the microscope and focus the facets of 

 the cornea in the usual way with a ^ " objective. You 

 then — and this is the important stag-e on which the result 

 depends — g-ently rack the objective upwards, causing- the 

 structure to appear to g-o out of focus, at the same time 

 moving- the cross on the mirror by means of a pointed 

 stick of Vy'ood. It will be evident where it is best to stop 

 raising- the objective, for the cross or the stick will be seen 

 in the facets. It then only remains for the cross to be so 

 set on the mirror that it appears in the centre of each of 

 the facets. There are many other ways in which the ef- 

 fect can be produced, a very pretty one being- to throw a 

 brilliant lig"ht on the face of a friend who sits at the side 

 of the microscope, and soarrang-ing- the mirror that the re- 

 flection of his face falls upon it and isag-ain transmitted to 

 the cornea. Also by a little scheming- the second hand of 

 a watch can be seen in each of the facets. When well shown, 

 these experiments always create astonishment and inter- 

 est. A little practice soon enables one to do them with 

 facilitv. 



MICROSCOPICAL SOCIETIES. 



Quekett Microsoopical Club. — 367th meeting- Friday, 

 March 17, at 20, Hanover-square. Mr. Rousselet read a 

 paper on "Torchosphaera," an extraordinary rotifer, not 

 as yet found in Eng-land. This animal is a sphere of about 

 the size of Volvox g-lobator, and two species are known, 

 one with the ciliary zone at the equator, thus dividing- it 

 into two equal halves,and another with the zone nearer the 

 pole, which is thus unequally divided. The org-ans are 

 contained in the lower hemisphere, and very clearly visi- 

 ble. A mounted specimen was exhibited under the micro- 

 scope. Mr. Soar read a note on a water-mite, a species of 

 atax, which he believed to be new. Mr. Lewis Wrig-ht, as- 



