PROCEEDINGS OF THE OHIO ACADEMY OF SCIENCE. 347 



that marveloLisly skilled technician of the old school, William 

 Kitchen Parker, with those of Gaupp's more recent work. 



This healthy progress in skull anatomy and embryology may 

 be paralleled by that in many other lines of morphology less 

 familiar to the writer, while in one branch, at least, of vertebrate 

 anatomy, — the study of the nervous system, — the advance has 

 been little short of revolutionary. 



MODERN NEUROLOGY 



In 1891 Kolliker, in a presidential address before the Ana- 

 tomische Gesellschaft in Munich, raised the seemingly isolated 

 question whether a nerve fibre ever exists without direct con- 

 nection with a ganglion cell. This question he answered in the 

 negative; and his answer was reiterated in the same year by 

 Waldeyer, who gave the name of neuron to this combination of 

 nerve fibre and ganglion cell. 



A certain independence of these neurons is argued from ex- 

 periments upon degeneration and regeneration and from embryo- 

 logical evidence of the origin of the neurons from independent 

 embryonic nerve cells or neuroblasts, — the latter brought to 

 practical demonstration by the brilliant work of Harrison, who 

 in 1907 succeeded in observing the actual development of nerve 

 fibres from isolated embryonic nerve cells cultivated in coagu- 

 lated lymph. The degree of this independence is still, however, 

 matter of dispute. In 1889 Ramcni y Cajal, on the basis of the 

 then new Golgi impregnation methods, had postulated an absokite 

 structural independence and a mere contact connection of neuron 

 with neuron ; on the other hand, and with even more delicate 

 technique. Apathy claims to demonstrate a system of delicate 

 fibrils, neurofibrillae, which ])ass without interruption from 

 neuron to neuron and form a marvelously intricate network 

 within the cell body and around its nucleus. Fortunately the 

 decision of this moot question is not essential to the efl:'ectiveness 

 of the neuron theory, which finds in the neuron the structural 

 unit and, to a certain extent, the physiological unit of the nerv- 

 ous system, — in fact, the only really nervous element of that 

 system. 



