xvi TO TEACHERS AND STUDENTS. 



object of the work to teach. Yet, this can be advantage- 

 ously done verbally, by every teacher; and his -pupils will 

 soon learn that, after becoming acquainted with the general 

 anatomy and physiology of an animal, whether it move 

 upon the dry land, float through the air, or seek the ocean 

 depths, its mode of life and general habits are immediately 

 discovered. This fact will become more clearly manifest as 

 we proceed ; and in the end, the student will comprehend 

 how Geologists are able to deduce, not only the habits of 

 an animal, but also the form of the animal itself, by exa- 

 mination of only a few of its bones. 



In order to study Geology with greater facility and suc- 

 cess, schools should be supplied with drawings, representing 

 the principal facts in the science : and also with some recent 

 marine, fluviatile, and terrestrial shells ; specimens of coral, 

 turf, and volcanic products, all distinctly labelled ; these, 

 after being pointed out, should be left accessible to the 

 pupils. 



To teach them the composition of the crust of the earth, 

 there should be drawings of the different stratifications, and 

 collections of fossils characteristic of the several formations. 

 Where fossils cannot be obtained, casts representing them 

 will serve a good purpose. Specimens of the various crys- 

 talline and sedimentary rocks should form a part of the 

 teacher's apparatus. 



To illustrate the various effects attributable to igneous 

 and aqueous causes, there should be some well-selected and 

 distinctly labelled specimens, of fossil-shells, of encrinites, 

 of echinideae, of madrepores, &c., in order to compare them 

 with those now existing. Drawings on a large scale, of 

 faults and crevices, of dykes and injected rocks, of basaltic 

 bosses, and of erosions attributable to water, should also be- 

 long to the school. During and after the lessons which 

 refer to a particular part of the subject, these specimens and 

 drawings should be exhibited and explained to the pupils. 



