MICROSCOPIC EXISTENCE. 



Collected by Henry Meigs, Recording Secretary of the American Institute. 



THE MICROSCOPE— By S. W. Leonard, F. M. S. 



It reveals the astounding fact that miles of strata of great thick- 

 ness are almost entirely composed of the skeletons and shells of 

 minute animals, in the formation of which ages must have elapsed, 

 miiiute vegetables and animal races in air, water at the bottom 

 of, as well as in oceans, from the ice of the poles to the burning 

 sands of deserts in the torrid zone. Of the minute vegetables 

 our botanists claim two, viz., Desmidicse,* which have a horny 

 skeleton and live in fresh water, the other are called Diatomacese,f 

 which are principally found in salt water, and whose skeletons 

 are of silica. It is scarcely yet settled whether these minute 

 beings are of vegetable or animal production. The botanists seem 

 at present to have the best of the day. These creatures puzzle 



Note by H. Meigs. Lindley, in his Vegetable Kingdom, treats of the algal alliance (sea 

 weed) , and places in the natural order of algals 



* 1st. Biatomacem. — These are crystalline, fragmentary bodies, brittle, multiplying by spon- 

 taneous separation. 



2d. Vesicular, filamentary or membranous bodies, multiplied by zoospores (living seeds), 

 generated in the interior at the expense of their green matter. These are Confervacem. 



3d. Fucacete, cellular or tubular unsymmetrical bodies, multiplied by simple spores formed 

 externally. 



Ith. Ceremiaceo;.— Cellular or tubular unsymmetrical bodies multiplied by tetraspores. 



5th. Characecc. — Tubalar symmetrically branched bodies multiplied by spiral coated 

 nucules filled with starch. 



* Desmidica. — Putrify ing very slowly, have no siliceous coat, and therefore alter their shape 

 in drying. When in perfection they are generally of an herbaceous green color, and not un- 

 frequently have the fragments divided into two portions, resembling each other in form but 

 sometimes differing in size much. This division is marked in Desmidium Mncosum by a shal- 

 low groove passing round the joint. The starch shows that these, as well as the Diatomaceas, 

 are vegetable and not animal. They are natives of still waters and oozy places in the north- 

 ern part of the world. Uses to man unknown. 



