AVTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, OCTOBER 4 



MICROSCOPIC EXAMINATION OF A FOSSIL FISH 



BRAIN 



ROY L. MOODIE 



Department of Anatomy, University of Illinois, Chicago 



TWO FIGURES 



When I published my first study (1) on the ganoid fish brains 

 from the Coal Measures of Kansas I had no material which could 

 be spared for sectioning, although I was extremely anxious to 

 determine if there were microscopic evidences of organic structure 

 in the petrified matei"ial. Since that paper appeared I have 

 received through the kindness of my friend, Bennett ]Mills Allen 

 of Kansas University, a series of nodules containing fish brains 

 which he had collected at the quarry and brought to Chicago for 

 me. Examination of all the specimens under the binocular 

 showed no essential differences in external form of the brain 

 from those previously described, so it was decided to devote one 

 of the brain-containing nodules to sectioning, to find, if possible, 

 traces of fiber paths or nuclei, or any organic structure which 

 might be preserved. 



Sections of an entire nodule with its contained brain, which 

 had been slightly chipped to determine the presence of neural 

 structures, were cut for me at the laboratories of the United 

 States Geological Survey by Mr, F. S. Reed, with a thickness of 

 about 12 microns. A favorable region is shown in the photomi- 

 crograph (fig. 2) at a magnification of 70 diameters. Owing to 

 the crystalline nature of the material it was not deemed neces- 

 sary to attempt staining, since an examination of the results of 

 Professor Lignier (2) who stained sections of fossil cycads with 

 vesuvine (Bismark-brown, or tri-amido-azobenzene) and Seitz 

 (3) who used an aqueous solution of Eosin, after a most elabo- 

 rate technique of preparation of the fossil bones of dinosaurs and 



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