OBSERVATIONS ON THE DEVELOPING NEURONES 



OF THE CEREBRAL CORTEX OF 



FOETAL CATS. 



By Shinkishi Hatai. 



{From the Neurological Laboratory of the University of Chicago.) 

 With Plate XIV. 



From studies on the human spinal cord, His ('89) in 1889 

 reached the following conclusions: In an early stage of the cen- 

 tral nervous system, the germ cell divides and produces 

 the daughter cells. Sooner or later each daughter cell sends 

 a process from one pole towards the periphery; that is, away 

 from the ventricle. This process is known as the earliest form- 

 ation of the neuraxone. Thus the neuraxone is the first process 

 to develop from the nerve cells or neuroblasts. Since His 

 made the above observation on the spinal cord of the human 

 embryo, it has been widely atcepted by almost all investigators 

 as a fact, and extended to the other divisions of the central 

 nervous system. 



In 1 899 VON Bechterew made observations on the cerebral 

 cortex of human embryos, which had been treated by the silver 

 impregnation method. Curiously enough, the nerve cells in the 

 earliest stage did not show the neuraxone, although the den- 

 drites stained beautifully. From this observation he concluded 

 that: "Die Axencylinder gehoren ofifenbar zu den spateren 

 Gebilden an den Nervenzellen, denn die urspriinglichen Anla- 

 gen der Nervenzellen entbehren noch ganz der Neuraxonen. 

 Manches spricht dafiir, dass die Axencylinder aus dem Kerne 

 der Nervenzellen, dem friiheren Embryonal-korperchen hervor- 

 wachsen, doch bedarf dies noch der Bestatigung. Die Collate- 

 ralen der Axencylinder wachsen immer spater als ihre Stamm- 

 fasern an den rosenkranzformigen Anschwellungen des letzteren 

 hervor." 



