516 W. H. HARRIS OX THE EMISSION OF MUSICAL NOTES 



I have already quoted Dr. Barmeister's description of the 

 internal aspect of the musical organ, but for convenience will 

 repeat it : " A small crescent- shaj^ed plate, 2(jjoji ichich are nine 

 parallel very delicate horny lamioiae." Do our flies of the pi-esent 

 century appear to confirm this statement ? I think they do not. 

 What we really find I will endeavour to explain. In so doing 

 I trust I may not commit myself to any statement incapable 

 of demonstration, for an error once started travels far, and in 

 nautical circles it is a well-known fact that a stern chase is the 

 longest to engage in. 



What really exists is, I think, as follows. There ai-e two 

 crescent-shaped rods, composed of chitin, joined together by 

 a ligament, thus forming a bow with elongated arms, the ends 

 of which appear to be quite free ; in outline they almost complete 

 an oval figure — a small space at the extremities of the arms alone 

 prevents the use of the term. A large bundle of muscles is 

 connected with the ligament, which, when contracted, cause the 

 two crescent-shaped rods to be deflected, turning the arms towards 

 each other ; when the pressure is relaxed they return to their 

 normal position. The rods support very delicate and pliant 

 membranes, which are folded or pleated in a very complicated 

 and extraordinary manner ; the free edges of the pleats are 

 considerably enlarged, and present a margin of considerable 

 extent packed away in the smallest possible space. There are 

 from tw^enty- three to twenty-five such pleats in the entire organ, 

 which they almost completely surround. 



Slide number three carries the dissection a stage further. It 

 contains one almost complete set of folds — unfortunately a few are 

 missing, but for our purpose this is immaterial — also one-half 

 of another set. They are mounted under pressure, and conse- 

 quently are somewhat distorted, but this has had the advantage 

 of displaying in one nearly entire organ both sides of the pleats, 

 for which purpose the additional half was originally mounted ; 

 moreover, a higher power objective may be usefully employed for 

 the examination. It will be observed that *at least three-fourths 

 of the pleated membrane extends above the crescent-shaped rods, 

 consequently any movement of the latter must cause the free 

 ends of the pleats to be considerably deflected. 



During the process of dissection I have satisfied myself that 

 the free edges of the pleats may be caused to almost, if not 

 comj^letely, approach each other, by operating the ligament as it 

 would doubtless be done by the muscles in the lifetime of the insect. 



