Literary Notices. xxv 



Dr. Lugaro has found in a study which we have noticed elsewhere in 

 this number that in different functional conditions the variations of the 

 quantity of the chromatic substance are very slight, while there is a much 

 more constant relation between the density of the stain and the size of the 

 cell. But there is another factor influencing the amount of chromatic 

 substance in the cell, a "specific factor," depending on the connections 

 of the cell or the normal intensity of its discharge. These points are 

 illustrated by several figures of the nerve cells of both vertebrates and 

 invertebrates. • c. j. h. 



The Pons Varolii of Mais.' 



Studies on human fetuses of five to seven months and on the 

 brains of young children by several of the newer methods. 



I. Substantia grisea pontis. These cells occupy the space between 

 the superficial transverse fibres of the pons and the internal lemniscus, 

 collecting in the interstices of \\\q Jibrae transversae pontis and the fas- 

 cicles of the pyramidal tract. They are of Golgi's first type and send 

 their nervous prolongations into the middle peduncle of both the same 

 and the opposite side, also into the ventral portion of the raphe. These 

 fibres are regarded as the scandent fibres of the cerebellar cortex, 

 whose terminal arborizations lie in connection with the Purkinje cells. 



II. i'oUaterah of the pyramidal fibres. These are two kinds, di- 

 rect and indirect, terminating in physiological contact with the den. 

 drites of tht- elements of the substantia grisea pontis. 



III. Pedunculus mcdius ccrebelU. The middle peduncles are com- 

 posed not only of the ascending fibres from the substantia grisea, but 

 also of descending fibres from the cells of Purkinje. Part of the latter 

 cross the raphe to terminate in ramifications among the elements of the 

 substantia grisea of the opposite side, part effect similar connections on 

 the same side, others pass via the raphe to the level of the teo-mentum 

 pontis of the same or the opposite side. They then pass either 2JS, fihrae 

 arcuatae internae or as ascending fibres of the raphe to participate in 

 the formation of the fasciculus medianus. Some fibres terminate among 

 the elements of the substantia reticularis grisea tegmenti pontis. To this 

 tract the author gives the ponderous name, "direct tract from the cere- 

 bellum to the nuclei of the tegmentum pontis." 



IV. Internal bundle of the pes pedunculi. The author has estab- 

 lished a direct and crossed connection between the Rolandic and fron- 



1 PusATERi, E. Sulla fine anatomia del ponte di Varolio nell'uomo. Nota 

 prelim. Rivista di Paid. nerv. e went., I, i, Jan., 1896. 



