SYSTEMATIC BOTANY. 107 



A satisfactory Press will be a matter of considerable moment. Two 

 plans are recommended, each having advantages peculiar to itself. The 

 simplest plan is to procure boards twelve by seventeen or eighteen inches, 

 one to be placed at the bottom and the other at the top of the pile of speci- 

 mens, and one, two or three at intervals between the dryers according to the 

 size of the pile and the character of the material in reference to moisture 

 contained. For weight, use a good-sized stone or two or three smaller ones. 

 A shallow box with sand or pebbles is perhaps still more convenient. A 

 press of this kind secures uniform and continuous pressure, and is not expen- 

 sive. Under no circumstances use a screw press ; many specimens would 

 probably be ruined by too much pressure, and besides, the pressure becomes 

 less as the pile of specimens gradually loses moisture. 



For ease of handling, convenience at home and in the field, neatness of 

 appearance combined with efficiency, a. Slat-press is to be recommended. 

 This can be made of wooden strips seventeen or eighteen inches long, seven- 

 eighths inch wide, and one-eighth inch thick, with cross pieces fourteen inches 

 long, five-eighths inch wide, and three-fourths inch thick. Seven of the slats 

 placed equally distant from each other should be nailed to four of the cleats 

 or cross pieces, an inch of each end of the latter projecting beyond the outer- 

 most slat on either side ; the press will therefore be twelve inches wide ex- 

 clusive of the projecting ends of the cleats. Two of the cleats should be at 

 the two ends of the set of slats and the other two placed equidistantly be- 

 tween. Seven slats and four cleats similarly nailed together would form the 

 other side or half of the press. To secure the necessary pressure on the 

 specimens pass strong cords, one on each side, attached to a cleat-end, con- 

 tinuously over the upper and lower projecting ends of all the cross pieces. 

 In each a shallow groove should be cut or filed to receive the continuous 

 cord ; a belaying pin, a groove sawed in the end of a cleat, or other device 

 should be added to secure the free end of the same. To make the press stUl 

 more efficient, " ventilators " should be inserted, one, two or more according 

 to amount in the press and the quantity of moisture in the specimens. The 

 ventilators, seventeen or eighteen inches long and twelve inches wide, can 

 be made of slats of same dimensions as those used in making the press ; use 

 fourteen of them in two equal series one above the other, between which 

 place four cross pieces one-half inch square and twelve inches long, disposed 

 to correspond in position with the four cleats on each half of the press. Such 

 ventilators can, of course, be used advantageously in any kind of press. 



For Mosses, Lichens and Fungi much less pressure generally is required. 

 Otherwise their manipulation would be in general as indicated above. They 

 should be collected only when in fruit. 



At the end of the collecting season the specimens should be perma- 

 nently mounted. The species- sheets should be of a good quality of 

 white calendered paper, cut eleven and one-half by sixteen and one-half 



