70 HISTORY OF FARM 



hairs for air-drifting, etc. Let the list include such data as, 

 kind of plant, size of seed (give measurements in millimeters: 

 if very small lay enough seeds, in line and touching each 

 other, upon a metric rule — such as Fig. i on p. 12 — to reach 

 one centimeter, and divide for average diameter), characters 

 affecting dispersal, characters of hull aifecting its 

 release: animals observed to feed upon it, etc. Let the 

 illustrations be simple outline sketches. As to names, if you 

 do not know them, save time by asking an instructor or some- 

 one who does know them. 



