384 PRACTICAL PHYSIOLOGY 



These effects can perhaps best be shown by examining the Martius- 

 Matzdorff l series of diagrams with a stereoscope. 



Visual Illusions. The study of Visual Illusions is somewhat beyond 

 the scope of the present work, but the student may advantageously 

 perform various of the experiments on the Milton Bradley Pseudoptics, 

 which illustrate many of these illusions. The Sections A, B, C, D, and 

 J are specially recommended in this connection. 



l The diagrams can be obtained from Winckelmann und Sohne, Berlin; 

 Petzoldt, Leipsic; or from Messrs. Baird & Tatlock, Cross Street, Hatton 

 Garden, London. From the latter firm can be obtained any of the instruments 

 mentioned above or the Milton Bradley Pseudoptics Series. 



