272 THE SECOND BOOK OF BOTANY. 



The specimens are to be fastened to the paper 

 with hot glue, about as thick as cream, laid on to the 

 plants with a camel's-hair pencil. Strips of thin, 

 gummed paper should then be fastened over the 

 thicker parts, to prevent their coming loose in han- 

 dling. Prepare your glue in an earthen or porcelain- 

 lined vessel, as corrosive sublimate acts on all com- 

 mon metals, and the brush, passing from plant to 

 glue again and again, will be likely to produce stains 

 if there is a trace of metal in the solution. 



EXERCISE LXXXI. 

 Labelling and arranging Plants. 



In some methods of studying botany the scientific 

 name of a plant is the first thing inquired for. But 

 here you have reached the last exercise of the book, 

 and have prepared a collection of plants for receiving 

 labels, while yet ignorant of this part of the subject. 

 It was, however, not the design of the present work 

 to teach you to label plants, with their scientific 

 names, for these are arrived at only by the study of 

 the groups known as genera and species, and they 

 are far too numerous, and are based upon too many 

 combinations of detail in structure, to make it possi- 

 ble to deal with them in a text-book like this. Be- 

 sides, in the true order of study, naming follows, and 

 depends upon classification. You have already done 

 something in this direction. You know the charac- 

 ters upon which classes are founded, have studied a 



