14 INTRODUCTION. 



display. Their beauty is sufficient reason for their 

 existence were there no other. When their varied and 

 exquisitely symmetrical forms are presented to the eye 

 under the microscope, a thrill of pleasure is experienced, 

 calm and pure, because free from all taint of passion, 

 and felt all the more intensely because nameless and in- 

 definite. We are brought face to face with perfection 

 in its most wonderful aspect the perfection of minute- 

 ness and detail ; with objects which bear most deeply 

 impressed upon them the signet-mark of their Maker ; 

 and we observe with speechless admiration that the 

 Divine attention is acuminated and His skill concen- 

 trated on these vital atoms; the last visible organism 

 vanishing from our view with the same Divine glory 

 upon it, as the last star that glimmers out of sight on 

 the remotest verge of space. 



These organisms further justify their existence to the 

 utilitarian, inasmuch as their study is well calculated to 

 exercise an educational influence which should not be 

 overlooked or despised. While they try the patience, 

 they exercise the faculties by forcing attention upon 

 details. Their minuteness, their general resemblance to 

 each other, their want in many cases of very prominent 

 or marked characteristics, render it a somewhat difficult 

 task to identify them. Long hours may often be spent 

 in ascertaining the name of a single species, and assign- 

 ing it its proper place in the tribe to which it belongs. 

 One species may often be confounded with another 

 closely allied, and days and weeks may elapse before 

 the eye and the mind, familiarized with their respective 

 details, can observe the distinctions between them. This 



