9 



pointed out that since this size has been adopted by all repre- 

 sentative herbariums, plants mounted on paper of other sizes 

 lose much of their value either for sale or exchange, as they 

 cannot readily be incorporated with other collections. When 

 the owner tires of such an herbarium, no one else wants it, 

 while if it consisted of sheets of the standard size, any botani- 

 cal institution would be glad to preserve it. The mounting 

 sheet may vary in weight from heavy writing paper (un- 

 ruled) to thin card-board, according to individual taste. The 

 material most used is called ledger paper, from its use in the 

 manufacture of such books. The heaviest grade of this is 

 the one suitable for ordinary plants. Each ream of 500 sheets 

 i i| by 16^ inches should weigh about twenty pounds or more 

 and cost about twenty cents a pound. It is not advisable to 

 use paper lighter than this, and for thick specimens, such 

 as the conifers, hickories, etc., light card-board should be used. 

 It is also well to look to the composition of the paper. A paper 

 made of wood-pulp will soon turn brown upon exposure to 

 the light, and is unfit for use. Care should also be taken tO' se- 

 lect a paper with a firm, hard surface. The price given above 

 is for the best grades of linen rag stock. 



Until very recently it was the practice to fasten the plants 

 to the sheets by strips of gummed paper. A better way has 

 now been devised, which consists in gluing them to the sheets. 

 The advantages of the new process are many. It is quicker, 

 neater, holds the plants more firmly, and is believed to pre- 

 serve them from injury better than any other method. The 

 only objection to it worth considering is that when the plants 

 are thus mounted they are mounted to stay, and can never 

 be taken from the sheets and their undersides examined. If 

 we had to deal with specimens made in the old way, with 

 every leaf and flower carefully pressed with the same side up, 

 this objection would have some weight, but ^ as plants are 

 now pressed there are always leaves enough showing the 

 undersides, and flowers enough to show all parts, making it 

 unnecessary to remove plants from the sheets. 



The first attempts at gluing plants were made with glue 

 such as cabinet-makers use. It was applied hot with a brush, 

 and besides being a tedious method, frequently wrinkled or 

 discolored the mounting paper. The kind now used is the 



