( clxviii ) 



tlie Diptera, also, the profile view is almost necessitated by the 

 organs themselves. I have discussed this question with some of 

 the best Continental insect anatomists, and they all agree that 

 the profile position is the essential point of view. It is evident 

 that in this, the natural position, all the organs are co-ordinated 

 together as natiu'e made them, as they are used by the insects 

 themselves, so that the relativity of part to part is at once 

 apparent to the ej^es of the observer. I do not mean to say 

 that it is never advisable to make other preparations, every 

 position is necessary for one's own instruction ; vertical and 

 flat, transparent and opaque are all needed sometimes where 

 it may be possible, but the educative and natural position is 

 the profile, and it should be placed in a cell with only sufficient 

 pressure from the coverglass to enable the mount to retain 

 its posture. 



It only remains for me now to press this line of research 

 strongly on my brother entomologists, there is a vast field 

 to be explored which will prove of the greatest interest to the 

 investigator and of the utmost value to science generally. 



