iv Journal of Comparative Neurology. 



of nerve cells and fibres in the central nervous system, the details of 

 which Dr. Berkley has himself so successfully investigated. He calls 

 attention to the fact that non-medullated nerve fibres are not known to 

 occur to any great extent in the cerebral cortex and expresses the belief 

 that the uncovered free endings of the lateral buds or gemmules of the 

 "psychic" cells of the cortex are the media of communication from 

 one neuron to another. These gemmule-bearing protoplasmic processes 

 are the first to suffer from the ravages of disease, the cell body degen- 

 erating later and the axis cylinder being affected last of all. " In 

 short, therefore," to quote from a recent editorial in the Journal of the 

 American Medical Association, ' ' the theory of Berkely as to the pathol- 

 ogy of dementia is as follows : The conduction of nerve stimuli to the 

 cell corpus is through the medium of the lateral gemmules of the proto- 

 plasmic processes ; that these are specially liable to injury from toxic or 

 morbid influences, and are the first portions of the neuron to atrophy 

 and disappear in certain diseases of the brain ; that with their atrophy 

 and consequent loss of function we have, first, confusion and incoor- 

 dination of psychic functioning, and finally with any widespread de- 

 generation of the cortical elements a permanent dementia ensues. His 

 conclusions have been deduced partly from examinations of human 

 brains and partly from experimental investigations on animals. He 

 gives with his paper a reproduction of micro-photographs, showing the 

 normal primordial process of a well educated man taken from an au- 

 topsy immediately after death, and of a corresponding process from a 

 subject of terminal dementia, showing the atrophy and absence of the 

 dendritic gemmules." c. j. h. 



The Functions of the Frontal Lobes.^ 



The satisfactory discrimination of the functions of the frontal lobes 

 from those of other cortical areas is a matter of great difficulty and the 

 attempts hitherto made have produced only ambiguous and conflicting 

 results. Ferrier has decided that the frontal lobes preside over atten- 

 tion while also presiding over motions of the eyes and head. Munk 

 and Luciani consider this region as a part of the Fiihlsphgere or senso- 

 rium and the motor centre of the dorsal muscles. Wundt and Hitzig 

 from a theoretical standpoint assume that it is the centre of higher psy- 

 chical functions. 



The author of the paper before us reaches similar conclusions and 

 offers interesting experimental evidence which if not entirely convinc- 



^BlANCHl, L. Brain, IV, 1895. 



