INTRODUCTION 



readily procured. Any butcher will furnish 

 sheep, pig, or beef eyes. Or, if one has the 

 time to visit the manager of a slaughter-house, 

 and make known to him one's needs, he will 

 supply enough eyes to carry through a host 

 of interesting dissections and experiments, and 

 give sufficient material for careful, orderly, 

 and fruitful study. Perhaps in no other kinds 

 of dissections will the investigator find so 

 much of interest, or have his efforts crowned 

 with such abundant and satisfactory results, 

 as in the dissections of the eye. But no one 

 should try to study all parts of the eye with 

 only one specimen. To try to do so is an error, 

 and a common one often committed by both 

 teachers and students. Specimens cost little 

 or nothing, and it is no more trouble to pre- 

 pare a half-dozen eyes for dissection than one. 

 The cost of preparation, too, is but little more 

 for a number of eyes than it is for one, and 

 may be no more in some instances. Besides, 

 having enough material on hand saves time in 

 case of a failure. Also, one can quickly repeat 

 a dissection, and so procure any number of 



20 



