252 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



single drop of water, thousands of Jiving creatures are 

 found, most of them invisible to the naked eye, and so 

 extremely minute, that many thousands of them will not 

 cover the space of a grain of sand ; the littleness into which 

 nature descends in these productions, nevertheless, offers 

 one of the most agreeable subjects for instruction and ad- 

 miration ; for bv comparing one of these minute living 

 creatures with a larger animal, whose appearance is terrific, 

 what a disproportion is observable, and what efforts of the 

 imagination does it not require to conceive the sm u'iness of 

 the parts of t'lis minute living creature, for it will appear 

 they are furni.-hed with as many or more members than the 

 largest animal ! They possess the apparatus necessary for 

 the circulation not only of the blood, but the atmosphere 

 through their bodies, and the patient experiments of Pro- 

 fessor Ehrenberg, of Berlin, have proved, that these ex- 

 ceedingly minute and interesting animals, to whom natural- 

 ists (the great Cuvier not excepted) had hitherto denied the 

 possession of any chemifying apparatus whatever, asserting 

 that they were nourished and sustained by imbibition or ab- 

 sorption, through their entire surface, have no less than 

 from four to forty sacs or stomachs. The mode of verifying 

 this fact is extremely simple, and consists in the following 

 process : a drop of water containing animalcula is to be 

 placed on a slip of glass, and a small quantity of solution of 

 vegetable coloring matter added to it with a camel-hair 

 pencil, the creatures will feed on this substance, and con- 

 sequently distend their stomachs. Another drop of clear 

 water must now be placed near the first, and by drawing a 

 fine point from one to the other, the animalcula from the 

 colored drop will escape into the clear drop, where they 

 may be examined with facility, and the color of the food 

 will enable the observer to count the stomachs. If the ex- 

 periment be repeated with another color, the creatures will 

 feed again, and other stomachs will be filled in like man- 

 ner. Care should be taken that the coloring be purely 

 vegetable, for if it contain any mineral particles, the animal- 

 cula will die, or at least instantly reject the food, so that 

 the experiment will fail. Indigo, carmine, sap-green, are 

 found to answer best ; in a word, this little world contains 

 objects of the number and variety of which we cannot have 

 the smallest idea without the assistance of the microscope. 



