24:2 The Microscope. 



J. G. Clark presided over an attractive exhibit consisting of 

 gold-plated diatoms {Arachnoidisciis Ehrenbergii), a double-stained 

 section of Dodder, parasitic upon Heath, and the beautiful peristomes 

 or spore-receptacles of the well-known moss, Funaria hygrometrica. 

 Neat explanatory cards were placed with each object. 



J. E. Davis exhibited a beautiful specimen of the " glass-rope 

 sponge " {Enplectella) under a bell-glass, and also its net-work of 

 silicious spicules under the microscope. He also showed a fine slide 

 of the interesting diatoms and polycistina dredged from the ocean's 

 bed at a depth of 1,750 fathoms. Some rough diamonds (Californiau 

 and South African) also attracted much attention. 



Dr. S. W. Dennis exhibited slides of the optic nerve under am- 

 plifications of 30 and 750 diameters respectively, from which a good 

 general understanding of its structure could be obtained. He also 

 showed a very tine injected section of cat's jaw with teeth in sitUy 

 and finally as '• Oh my " slides, a fine example of that gastronomic 

 dainty, the cheese mite, and a lively collection of vinegar eels. 



A fine section through the entire human eye was shown under a 

 low power by Dr. Henry Ferrer, who also exhibited excellent pre- 

 parations of the human retina, and of the embryonic eye of call 

 The elegant Zeiss stand and apochromatic objectives belonging to 

 this gentleman received much admiring attention fi'om the experts 

 present. 



Prof. Hank's exhibit of an American coin was an interesting 

 case of making much out of little. It also evidenced the curious 

 fact of " inversion of relief," or the seeing of depressions by some 

 observers, where others see elevations. 



Two beautiful slides of arranged diatoms were shown by Dr. J. 

 H. Hatch. One of them was of peculiar interest from its containing 

 the monogram of the society, in diatoms, and having been presented 

 to it by one of its corresponding members, Captain Mortimer. 



The exhibit of A. M. Hickox comprised a fine moimt of the 

 head of the jumping-spider {salticus scenecus,) showing the beauti- 

 ful gleaming eyes, and a scale of an eel under polarized light and 

 selenite plate, bringing out all the well-known gorgeous prismatic 

 hues. 



Diatoms shown under different styles of illumination, formed 

 the exhibit of Henry C. Hyde. The slide which attracted most 

 admiring comment was one of arranged diatoms (mounted by Rinn- 

 bock), shown on a beautiful dark ground obtained by Zentmayer's 

 Abbe condenser. 



