Introduction. xi 



steadiness of your hand and you will probably get along all 

 right. Use a good, black drawing ink, and a clean, fine-pointed 

 pen. Trace from left to right, drawing the pen slanting well 

 back so it will slide easily. Work always on the " out curve," 

 i.e. supposing the drawing is right side up, begin at the head 

 and trace the outline of the back ; when you have reached the 

 tail, turn the drawing upside down, and trace the ventral mar- 

 gin, beginning with the tail end. By this method you will always 

 be making an easy curve, with the elbow as the center of the 

 curve. Follow this plan wherever there is a curved line, always 

 turning the drawing so that the concave side of the curve is 

 toward you. Try to give an even, steady motion. Whenever 

 possible avoid going over the line a second time with the pen. 

 If necessary to trace over, or especially if you stop to re-ink, 

 begin a little back of where you stopped, in order to make the 

 line smooth and even. If you attempt to trace by pushing the 

 pen, or even by drawing it sidewise, it may occasionally " stick 

 and sputter " ; drawing the pen lengthwise, as above suggested, 

 seldom makes any such trouble. 



Now comes the labeling. Place the label on each part, or 

 very close to it. Never letter, or number, the parts, with ex- 

 planations below. This method is wasteful of time and eye- 

 sight. Plan the labeling carefully before you begin. Do not 

 make the labels crowded in one part and scattered in another if 

 you can distribute them more evenly. Avoid drawing a dotted 

 line across one organ to the one designated. Organs near the 

 margin may well be labeled outside, using dotted lines if neces- 

 sary. Organs far from the outside are best labeled on the organ 

 itself in the most available place. Print all labels, using the 

 gothic type, that is, without crosses at the ends of the lines. To 

 insure uniformity in the letters make parallel guide lines with 

 the pencil ; then letter with pencil ; after tracing the letters 

 with ink, erase the guide lines. The general label, below, 

 should be larger than the detail labels. See the cut of the perch 

 as an example of labeling. 



