ON THE STUDY OF ZOOLOGY 367 



sions which neither change nor pass away, but, on the 

 contrary, form fixed centres, about which other truths 

 aggregate by natural affinity. 



Therefore, the great business of the scientific teacher is, 

 to imprint the fundamental, irrefragable facts of his science, 

 not only by words upon the mind, but by sensible im- 

 pressions upon the eye, and ear, and touch of the student, 

 in so complete a manner, that every term used, or law 

 enunciated, should afterwards call up vivid images of the 

 particular structural, or other, facts which furnished the 

 demonstration of the law, or the illustration of the term. 



Now this important operation can only be achieved by 

 constant demonstration, which may take place to a certain 

 imperfect extent during a lecture, but which ought also 

 to be carried on independently, and which should be 

 addressed to each individual student, the teacher endeavour- 

 ing, not so much to show a thing to the learner, as to make 

 him see it for himself. 



I am well aware that there are great practical difficulties 

 in the way of effectual zoological demonstrations. The 

 dissection of animals is not altogether pleasant, and requires 

 much time ; nor is it easy to secure an adequate supply of 

 the needful specimens. The botanist has here a great 

 advantage ; his specimens are easily obtained, are clean 

 and wholesome, and can be dissected in a private house as 

 well as anywhere else ; and hence, I believe, the fact, that 

 botany is so much more readily and better taught than 

 its sister science. But, be it difficult or be it easy, if 

 zoological science is to be properly studied, demonstration, 

 and, consequently, dissection, must be had. Without it, 

 no man can have a really sound knowledge of animal 

 organization. 



A good deal may be done, however, without actual dis- 

 section on the student's part, by demonstration upon 

 specimens and preparations ; and in all probability it 

 would not be very difficult, were the demand sufficient, to 

 organize collections of such objects, sufficient for all the 

 purposes of elementary teaching, at a comparatively cheap 

 rate. Even without these, much might be effected, if the 

 zoological collections, which are open to the public, were 

 arranged according to what has been termed the " typical 

 principle " ; that is to say, if the specimens exposed to 

 public view were so selected that the public could learn 

 something from them, instead of being, as at present, 



