i HINTS ON DRAWING 15 



canal yellow, the arteries red, the veins blue, glands brown, cartilage 

 green, and so on. 



Make your drawings on one side of the page only ; the opposite side 

 can then be used for explanations of the figures. 



Never insert on your original sketches anything you 'have not actually 

 seen ; you can copy as many other figures as you like from various 

 sources, but these should be kept apart from your own original 

 drawings. 



Directions for the examination of the external characters of the adult 

 frog, as described in this chapter, are given at the end of Chapter II., 

 p. 31 ; and of the eggs and tadpoles in Chapter XII., p. 212. 



