526 



Comparative Animal Physiology 



changes in the wing beat which will restore the normal attitude of the 

 flying insect. 



The morphological analysis of the structure and orientation of the sense 

 oroans may be summarized as follows: 



I. Sensitive to strains produced by vertical 

 oscillation of the haltere 



1 . Dorsal scapal plate 



2. Ventral " 



3. Dorsal Hicks papillae 



4. Ventral 



5. Small chordotonal organ 



II. Sensitive to strains produced by gyroscopic torque 



1 . Basal plate 



2. Large chordotonal organ 



The halteres function as gyroscopic organs of equilibrium sense. 



Fig. 195. Diagram to illustrate the mechanics of haltere articulations. Pringle. 



SUMMARY 



Mechanoreceptors are important in the positioning of animals. Some- 

 times the "rest" position is one of contact stimulus on one side, as in the 

 orientation of blind fish on a stream bottom or as in the inhibition of 

 insect flight by tarsal contact. Sometimes there is a balance of bilateral 



