No. 533] PHOTOGEXIC ORGANS OF LAMP YB1DJE 313 



the photogenic organs connect near the breathing spiracle 

 with the tracheae which supply the other organs, and that 

 they closely resemble the latter tracheae in structure; 

 (c) the view that the photogenic process is an oxidation 

 is borne out by the structure of the photogenic organs. 



We wish to express our appreciation of the assistance 

 of Director John F. Anderson, of the hygienic labora- 

 tory, and Dr. Norman Roberts and Mr. Geo. F. Leonard, 

 of that laboratory, and we are indebted to Dr. E. A. 

 Schwarz and Mr. H. S. Barber, of the U. S. National 

 Museum, for their kindness in supplying entomologic 

 information, and to Professor W. A. Kepner, of the Uni- 

 versity of Virginia, for criticism and advice. 



No attempt will be made here to give a complete list 

 of the references to the literature of even the histology 

 of the luminous tissues; so far as the latter branch of 

 the subject is concerned, it is pretty thoroughly covered 

 by the bibliography given by Miss Townsend, and the 

 most complete bibliography yet published of the whole 

 subject of physiologic light is contained in Mangold's 

 extensive and interesting review cited as reference No. 

 5, below. 



2. Townsend. The Histology of the Light Organs of Photinus margincllus. 

 Amer. Nat., 1904, Vol. 38, pp. 127-151. 



1907 ; Lampvrida., Part !». < uleopterorum Catalogus, Schenkling-Junk, 

 Berlin, 1909. 



Zocl. Anz., 1889, Vol. 12, pp. 594-600. 



