THE LITERARY 



OP THE LINNiEAN ASSOCIATION OP PENNSYLVANIA COLLEGE. 



Vol. 11 [. JUNE, 1847. No. 7. 



NATURAL HISTOPvY RECREATIONS. NO. II. 



BY AN AMATEUR. 



In the February number of this Journal, 1 gave a paper on those 

 minute and remarkable animals called Infusoria, from the fact of their 

 being developed in infusions of vegetable or animal substances. 



Since that time, I have been amusing myself and friends by a more 

 scientific examination of them, and we here give you a few of the re- 

 sults. 



A good microscope is essential for this pursuit. There is no optical 

 instrument which affords more solid amusement then this, for it displays 

 to the wondering gaze the most extraordinary operations of nature. I 

 bought one in Paris of the celebrated Chevalier manufacture, which cost 

 me there about twenty-five dollars, and which answers every purpose. — 

 A cheaper one would serve for ordinary observation. 



It will not appear strange to those who have any idea of the pro- 

 gress of modern science to hear, that these infinitesimal animals, most 

 of which are invisible to the naked eye, have been systematized, classi- 

 fied and named as to genera and species, just as tlie quadrupeds, fishes 

 and birds have been. Splendid works have been written on the subject 

 of these animals, most of which are illustrated with finely engraved and 

 colored figures of them. 



I shall mention, at present, but a few species, beginning with the most 

 simply organized. 



The first class embraces those, which have a stomach composed 

 of many sacs, but have no intestinal canal, and hence no posterior aper- 

 ture. 



These are the smallest of all known organisms, and how large do 

 you suppose they are ? It seems ridiculous to apply to them any word 

 indicating size, for often they arc not the SOOOlli part of a line in length ! 



