4 DISEASES OF FIELD & GARDEN CROPS. [OH. 



they are original, and have all been drawn direct from 

 nature to uniform scales, and engraved by ourselves, so 

 that the comparative degrees, of largeness or smallness 

 of the different parts of all the fungi described may be 

 understood at a glance. Nothing is more wretched than 

 the copying and recopying of book illustrations, too often 

 bad ones, without examination or verification. To such 

 an extent is this copyism at times extended, that in some 

 instances, only one original drawing has ever been made, 

 and every succeeding drawing, whether English, French, 

 or German, is a mere slavish copy. The description, too, 

 as well as the drawing, of one person is too often taken 

 on trust alone for an indefinite period of time. The com- 

 prehension of some published illustrations is sometimes 

 made difficult by the diverse and odd powers of magni- 

 fication, such as xlV, x!31, x316, etc., so that after 

 the examination of a few illustrations a student's mind 

 becomes greatly confused as to the relative sizes of the 

 objects illustrated. All magnified figures should be in 

 tens, hundreds, or thousands. Sometimes certain authors 

 have illustrated fungi and omitted the amount of mag- 

 nification upon the plates ; they have simply inserted 

 "slightly enlarged," "greatly enlarged," "still further 

 enlarged," etc. ; and the fact is certainly not creditable to 

 the copyists when we say that every illustration copied 

 from certain works with which we are acquainted repro- 

 duces these almost unmeaning terms. The fact shows that 

 the whole phenomena described by certain writers have 

 simply been taken by their successors on faith, and that 

 no single copyist has taken the trouble to measure and 

 verify for himself. 



Students of nature should take very little on trust, for 

 the sharpest observer is liable to make a mistake in what 

 he thinks he sees, or in the meaning he attaches to what 

 he sees, or fancies he sees. Therefore, as far as possible, 

 every one should observe and think for himself, not with 

 a view towards finding fault with other observers, but to 



