12 INTRODUCTION. 



object. That they should glance down the list to see if by any 

 chance a green specimen may have been provided for, does not oc- 

 cur to them; they toss the paper aside, and laugh at the utter folly of 

 the statement that any intelligent person should be able to use a 

 key. The truth is that inability to use these valuable aids is an evi- 

 dence of a defect in the mental organization. Such critics are forced 

 to page through the monographs they attempt to study, with great 

 loss of time and with much labor, to find the information that may 

 be wanted; whereas with the object and a key to its class in hand the 

 labor becomes a delight, and the result a valuable acquisition, be- 

 cause no key to any department can be used even to a limited extent 

 without teaching the student many facts that he might otherwise have 

 overlooked. 



A table of the kind will draw attention to the morphology of the 

 object in a way that will lead not only to its proper classification, 

 but to something much more important, the enlarging of the stu- 

 dent's powers of observation. Some of those that oppose the use of 

 artificial keys are themselves compelled not only to page through an 

 unfamiliar monograph, but in many instances to scan the pictures for 

 the light they are groping after; and failing pictures they guess as 

 to the character of the object from its resemblance to something re- 

 motely similar, and in the end, at great expense of time, and perhaps 

 of temper, may get a clue that may lead them to the goal they have 

 been so laboriously seeking. With the intelligent use of an artificial 

 key the place, the character, and even so unimportant a matter as 

 the name, can be rapidly obtained, and the student be led on to fur- 

 ther study and investigation. 



It is always encouraging to feel that by one's efforts a way has 

 been opened to further conquests, or even that a path has been cut to 

 some previously unknown view. This the use of artificial keys 

 always accomplishes. When the beginner feels that he can do some- 

 thing unaided he is inspired to do more. When he feels that he has 

 travelled alone through some pathway in some department 

 of natural science, he is anxious to go further. One step taken 

 with the aid of an artificial key is sure to be an encouragement toward 

 another. The powers of observation are increased. The ability 

 to balance one thing against another is cultivated. In a word, an 

 artificial key can be made one of the most important aids in the 

 mental development ot the beginner that can be imagined. The ob- 

 server that scoffs at these aids, the observer that refuses to take 

 advantage of them, is doing a foolish thing and losing a good one. 



