8 THE AMERICAN MONTHLY [Jan., 



and in this way Paramecium destroyes prodigious num- 

 bers of Bacteria. For all this, however, the hosts of 

 Bacteria do not appear to be very materially reduced. 

 Many other infusorians feed upon Bacteria, and some of 

 them are so small that they can only capture one Bac- 

 terium at a time. 



Enough has now been said to convey some idea of the 

 variety and abundance of microscopic life in these tanks. 

 Although no opportunity has come for the writer to in- 

 vestigate the Schenley Park conservatory, their tanks 

 will doubtless prove equally rich and interesting. 



Any one of the species referred to in this paper will 

 furnish work enough for a year, or even years, and abun- 

 dant material for an interesting monograph. As every 

 fresh gathering of the same species is apt to supply 

 some new feature, one who has taken up these studies 

 with any degree of success, is prone to be lured on fur- 

 ther and further into this world of enchantment. Every 

 humble worker, provided he makes truthful drawings 

 and notes of what comes to his view under the glass, 

 stands a chance to do something of value. 



In hunting for animalcules one must be prepared to 

 encounter a goodly share of disappointments. Some- 

 times this is due to his own want of skill or patience. 

 Yet, animalcules come and go in the most unaccountable 

 ways. One season a particularly interesting kind may 

 be found in profusion, and then not appear again for 

 years. This uncertainty only adds zest to the search for 

 these most interesting objects of which there will always 

 be some to repay all the time and trouble spent in ob- 

 taining them. 



Some may regard all this time and labor as wasted? 

 but to such it may be answered that if Natuer has tak- 

 en such pains to adorn with beauty and endow with 

 marvellous contrivances and instincts these minute be- 

 ings, it is surely proper for us to search out these won- 



