314 



EEOEEATIVE SCIENCE. 



then vanislied in the gloom ; one after another 

 the tiny blades caught the gleam, making a 

 circle of brUliant sparks of variegated light. 

 A lady who witnessed the performance corn- 



Encysted Vorticella, showing the obliteration of spe- 

 cial organs by the advancement of the process. — 

 Pritchard, 



pared it to that of street jugglers throwing 

 up and catching a succession of golden balls, 

 and called the Vorticella a conjuror with co- 

 loured flames. 



Before leaving the Vorticella, we must say 

 a few words on the motion of cilia. These in- 

 teresting appendages are very common conco- 

 mitants of animal life, and give likewise mo- 

 tion to many vegetable forms. By what power 

 they move no one knows ; but it is not mus- 

 cular, or it would not be exhibited by the 

 vegetable kingdom. It is affirmed not to be 

 affected by electricity, or by poisons which do 

 not damage the tissue from which it springs, 

 and the motion sometimes continues long 

 afterdeath. The authorsof the "Micrographic 

 Dictionary " tell us, " cilia are found in all the 

 vertebrata and the invertebrata, excluding 

 the Crustacea, arachnida, and insecta." In 

 man they occur in what is called the ciliated 

 epithelium, or membrane lining the larynx, 

 trachea, nose, and other cavities, where their 

 action takes place without our knowledge or 

 control. In the vegetable world their move- 

 ments are of course invohmtary, and pro- 

 bably they are so in many of the infusoria ; 

 but they nevertheless are the organs of mo- 

 tion in creatures sufficiently high in the animal 

 scale — like the Rotifers, for example — to be 

 apparently under the control of something 

 like a will. 



The last denizen of our bottles we shall 

 mention is the Closterium lunula, or beauti- 

 ful crescent, moon-shnped, transparent cell, 



nearly filled with the emerald-green vegetable 

 substance caUed ChloropJiyll. These exqui- 

 site objects were at one time supposed to be- 

 long to the animal kingdom ; but now, with 

 their fellow Desmids (Desmidice), they are 

 regarded as among the lower forms of vege- 

 table life. They move through the water 

 with a graceful, dignified sort of motion, pro- 

 duced no one knows how ; for the authors of 

 the " Micrographic Dictionary," in the new 

 edition of that work, distinctly deny the 

 ciliary theory which Mr. Osborne puts forth. 

 The one before us is a beautiful object, 

 magnified from 100 to 150 diameters ; but a 

 higher power (400 or 600) renders conspi- 

 cuous a fidgetty motion of angular-looking 

 particles near either extremity of the delicate 

 crescent. 



From the great variety of their forms, 

 ^^^-;^ and the brilliancy of 



their colours, the Des- 

 mids are great favourites 

 with microscopic observ- 

 ers ; but their best friends 

 have not contested — as is 

 still done with the Dia- 

 toms — the decision which 

 Closterium lunula, places them in the vege- 

 table world, and ranks them among the con- 

 fervoid Alffce. Like other plants, they evolve 

 oxygen under the influence of light, and for 

 the most part prefer clear water in open 

 situations. Many are found on the surface 

 of mud, others attached to plants, and they 

 have some means of moving towards the 

 light ; which is convenient for finding them 

 when they have become buried in the dirt. 

 Although their rank is low, they have an 

 ancient pedigree, and flints abound in fossil 

 remains of the spore-vessels {Sporangia) of 

 Desmids, which lived long, long ago, myriads 

 of ages nearer than we are to the dawn of 



time. 



Henet J. Slack. 



