ILLUSTRATIONS FOR PUBLICATION 



191 



heavy horizontal line. Some use only these two lines ; but it looks better 

 to rule, in lighter lines, the space between. Figures and letters can be 

 pasted on, or may be indicated in pencil and the printer can do the 

 rest. If you choose to do your own lettering. Exercises in Lettering, 

 "Slant Gothic," by George G. Greene, published by the Bruce Publish- 

 ing Company, Milwaukee, Wisconsin, will be helpful. 



Where several curves are to be shown, the ideal method would be to 

 use different colors; but, in practically all scientific journals the expense 

 makes this method prohibitive. So, use a solid heavy line for one 

 curve, a broken line for another, a dotted line for another, etc. 



rndoa'armis 



\Per/cyc/e 

 ,Ph/oem 



Endodermis 

 - Pericucle 



Ph/oem 

 Xu/em 



Fig. 35. — Two drawings of a part of a vascular bundle of Pteris aquiUna, A showing a poor 

 style, looking as if the layer of cells just outside the endodermis might be the outer border of the 

 structure; B, a better style, showing that the cells just outside the endodermis are not the outer 

 border. X150. 



The camera lucida minimizes the amount of skill required in mak- 

 ing highly magnified drawings. Draw first with a pencil, making very 

 light lines which will easily rub out; then ink while you still have the 

 preparation under the microscope for constant reference. Such draw- 

 ings are almost always reproduced by the zinc-etching process. Pen- 

 cil drawings can be reproduced by the more expensive photolitho- 

 graphic method, or by the still more expensive lithographic method. 

 They can also be reproduced, although not so satisfactorily, by the 

 halftone process. 



In making a detail from a tissue, do not make a border of entire 

 cells so that it will look like an outer margin ; but leave it so that it will 

 look like a detail which had more surrounding it (Fig. 35). 



