CARPS. 



213 



diameters, the former is seen to be a layer of 

 loose membranous cells of an orange colour, in 

 what are properly called the Gold-fishes, and 

 whitish or pellucid, in the Silver-fishes. If we 

 now add a minute drop of water to the mass, and 

 gently agitate it with the point of a needle, and 

 again submit it to the microscope, we shall have a 

 beautiful and interesting spectacle. The water 

 around the mass is seen to be full of an infinite 

 number of flat spicules or crystals, varying much 

 in size, but of very constant form, a flat oblong 

 prism with angular ends, as represented in the 

 accompanying engraving. By transmitted light 

 they are so transparent 

 and filmy as to be only 

 just discernible ; but by 

 reflected light, and espe- 

 cially under the sun's rays, 

 they flash like plates of 

 polished steel. But what 

 appears most singular, 

 is that each spicula is 

 perpetually vibrating and 

 quivering with a motion apparently quite spon- 

 taneous, but probably to be referred to slight 

 vibrations of the water in which they float ; and 

 each independently of the rest, so as to convey the 

 impression to the observer that each is animated 

 with life, though the scale be taken from a fish 

 some days dead. Owing to this irregular motion, 

 and consequent change of position, each spicula, 

 as it assumes or leaves the reflecting angle, is 

 momentarily brightening or waning, flashing out, 

 , or retiring into darkness, producing a magic effect 

 on the admiring observer. To this property, we 



SPICULiE OF GOLD-FISH S 

 SCALE. 



