(I"'roin tili; Anatomical l.alioratdry «if the L'liivei'sity of Cliicago.) 



The relations of mitochondria and other cytoplasmic 

 constituents in spinal ganglion cells of the pigeon. 



By 

 K. V. Co »dry. 



(With plates XV— XVII.) 



Contents. 



1. Introduction 473 



2. Tiie neixrosomes of Held 476 



3. Mitochondria 479 



4. The relation of the nenrosomes of Held to mitochondria 487 



5. Nissl substance, canalicular apparatus and neurofibrils 489 



6. Conclusions 497 



7. Bibliography 499 



8. Explanation of figures 502 



1. Introduction. 



The structure of tlie cytoplasm of uerve cells is of absorbino" 

 interest to the auatomist, the psychiatrist and to luaiiy others. The 

 reason for this is self-evident. 'l'li(> optically homoii'eneous o-rcnind 

 substance has baffled all attempts at fiKpiiiy: hut the Xissl substance, 

 the neurofibrils, the canalicular ap])aratus and the niitochondi'ia. wliich 

 are imbedded in it. have formed centres for most dilig-ent research. 



The Nissl substance was first observed by Flemmin^i- in 1882: 

 but it was not until several years later that Xissl published the 

 details of his famous method, and in doing so opened up a vast field 

 for original investigation. And investigators were not slow \o make 

 use of the opporttinity thus offered, for these cytoplasmii- granulations 



