—So- 



One should have the following implements if possible : A pair 

 of fine pointed forceps with comparatively large surface of con- 

 tact at the points, a pair of small, fine-pointed, sharp scissors, dis- 

 secting needles, a sharp scapel or razor and a stick of pith. 



The leaves should be removed with the forceps by seizing 

 them near their bases and stripping downward; these are then 

 put in a drop of water on a slide and covered with a cover glass ; 

 in this drop of water should be placed also a portion of the branch 

 from which the leaves have been stripped. An examination of 

 this last will show whether the bases of the leaves are decurrent 

 or not and will give a profile view of the leaves that will tell 

 whether there are any teeth or papillae on their backs. With the 

 hair-caps and their allies and some other mosses, a cross-section of 

 the leaves is often necessary to defmtely determine the species. 

 This often seems very difficult to a beginner but is really quite 

 simple unless very beautiful sections are desired. The most com- 

 mon method is to split a stick of pith a little distance and insert a 

 bunch of leaves in the cleft, pressing the sides together with the 

 thumb and finger of the left hand. Then cut thin sections of pith 

 and leaves with a very sharp razor or scapel. The pith should be 

 thoroughly moistened and there should be water on the upper sur- 

 face of the razor to float away the sections cut. After a number of 

 sections have been made, all the mass of pith and leaf sections 

 should be removed to a drop of water on a slide and the pith and 

 large pieces of leaves should be removed. Pith can be obtained 

 from young elder shoots or the stems of the flowering raspberry, or 

 if nothing better is at hand the pith of a cornstalk can be used. 

 Mrs. Britton thinks this method is "more bother than it is worth 

 for all simple leaf sections," * but recommends it for other sections. 

 She places a number of the leaves side by side in the same direc- 

 tion so that they may be easily held firm with the thumb nail of the 

 left hand — " begin cutting at the tips of the leaves" ( using a razor 

 or sharp knife) "moving the nail from side to side and working 

 downward to the lower half of the leaf." I have often used 

 another method with success. Grasp a bunch of leaves between 

 the thumb and forefinger of the left hand and with the scissors 

 (which must be sharp) cut section after section from the bunch 

 as thin as possible, and among the mass of sections will be found 

 some that will show the desired structures. If the leaves are very 

 small, a whole stem or branch covered with leaves can be sec- 

 tioned without first removing the leaves. 

 ^Observer for May, 1894. 



