xviii Journal of Comparative Neurology. 



tain hairs in consonance with given tones. The author of the pres- 

 ent paper gives a detailed account of the structure and development 

 but adds nothing of importance upon the functions. He accepts the 

 evidence for the auditory nature of the apparatus but concludes that 

 it was originally adapted simply for tactile sensation and may still re- 

 tain, in part at least, the original function. 



We reproduce part of the authors' summary. "In most orders 

 of insects there is in the second joint of the antennae a highly devel- 

 oped sensory organ. This organ consists essentially of ganglion cells, 

 which are produced into long rod-like processes or are connected by 

 threads with rods. The rods terminate either in pores of the skin of 

 the joint between the second and third segments or in chitinous pro- 

 cesses of the peripheral margin. In many of the culicidse and chir- 

 ononidas the organ is greatly developed, while in the female the struc- 

 ture is simpler and more nearly approaches the type. This greater 

 development in the male indicates a relation to the sexual life. The 

 proton of Johnston's organ in the larva of cuculidse and chirononidae 

 first appears as a ring-like fold of the hypodermal invaginated anten- 

 nary tube near the base of the head. Out of this fold are formed the 

 ganglion cells and rods, the latter by the fusion of cells." 



C. L. H. 



