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THE AMERICAN NATURALIST 



[Vol. XLI 



the neck region elongates, and a new set of segments may be produced, 

 consisting like the first set of an anterior and a posterior group of 

 segments. An account of this investigation -vvas published in the 

 Biological Bulletin, 1900, vol. 11, p. 202-229. 



Professor R. Ileymons, curator of the zoological museum in Berlin, 

 showed several larvae of a beetle of the genus Tenebrio which had 

 macroscopic rudiments of wings,— a ])ivir on the nu\sotli()rax and 

 metathorax respectively. Since the ]i\v\iw were not reared, the time 

 of the first appearance of the rtidiineiiis was noi (leicniiiiied. it A\as 

 observed that small rudiments were shed m iiioliiiijj, hut that the 

 larger ones remained and finallv expamled into iIh- \mii-s ot the adiih. 

 External wing rudiiniMits on hirvae ot iiise( i> iiiider-oiiiu ((>ni|)lete 

 metamorphosis are verv lare. Thev ha\e ln-en obserxed in a tew 

 other coleopterous larvae (Aiithroi us ntmis] and aie |)iot)al)l\ "in- 

 stances of premature d(>vel()pmcnt. ' 



Dr. F. E. Lutz of Cold Spring Harbor exhibited specimens of the 

 fly Drosophila, showing variations in the venr.tion ot its wings. The 

 arrangement of the veins in wings of flics is usually (luite constant. 

 A disturbance of the normal arrangement soinetiiiH s occurs in Dro- 

 sophila in nature, and by breeding selected individuals the disturbing 

 factor has been increased. It is inherited soim w hai . Imi not abso- 

 lutelv, in Mendelian fashion, and ap])ears to be iiKh pendent ot (Miviron- 



