48 BULLETIN OF THE LABORATORIES. 



made a discovery, but to have failed to appreciate the relations which 

 obtain in the primary disposition of the cortical elements." 



The study of the cortex in animals which, like rodents, have an 

 unconvoluted cerebrum, proves that Betz was entirely right in associ- 

 ating special motor areas with enlarged pyramids, as we hope to suf- 

 ficiently show. The real basis for subsequent work is indicated by the 

 following passage from Meynert : 



"No morbid change and no physiological experuiient gives us any 

 reason to hope that we shall be able to explain the difference in form 

 of cortical elements in closely neighboring layers. Morphological in- 

 terpretation is the only method which can cDme to our rescue The 

 nerve corpuscles of the gray anterior horns of the spinal cord, of the 

 central nuclei of the hypoglossal, facial and abducens nerves, and as 

 far upwards as the oculomotor nerve, all show long, slender cell forms 

 with numerous processes. These processes seem to arise with a broad 

 base from the body of the cell. The same peculiarities of configura- 

 tion which we observe in those nerve cells, which are conaected with 

 the centrifugal nerve tracts, are found in the cortical pyramids, and 

 there can only be explained by the similarity in the disLribution of 

 those bodies. Gerlach has compared the median base process with 

 those spinal cell processes which enter the anterior roots. The 

 granules of the fourth cortical layer, which are distinguished from the 

 free nuclei by their size and protoplasm, from the spider and spindle 

 shaped cells by the distinct boundary of their protoplasm, and by a 

 lesser number of stout processes, may be likened to those branched 

 ganglionic cells which occur in centres connected with centripetally 

 conducting tracts.'^ — {Meynert, Psychiatry, p. 66.) 



The paper of Golgi (Re vista sperimentale, 1883), has remained 

 inaccessible to us but, judging from excerpts. Koelliker's criticism 

 (Anat. Anzeiger, 1888, II, No. 15,) seemsjustified. Especially we feel 

 constrained to call attention to Koelliker's suggestion that the outer 

 zone contains fibre tracts of major importance. This we had previ- 

 ously determined and in the case of lower vertebrates the existence of 

 j)rominent tracts in the so called neuroglia layer is well demonstrated. 



Koelliker says: " Sehr eigentuemlich ist, was Golgi ueber die 

 axencylinderfortsaetze die nervenzellen mittheilt. Dieselben sollen in 

 zwei Formen vonkommen. Bei den centrifiigal-wirkenden (motoris- 

 chen) Zellen soil der Fortsatz im ganzen mit gleichbleibenden Staerke 

 zum axencylinder einem dunkelrandigen Fasser werden, auserdem 



