DEGENEKATIONS FROM LESIONS OF TEMPORAL CORTEX. 151 



were investigated, fifteen of wliich were monkeys and a like 

 number marmoset brains. Througb these, sections were made 

 in various directions, horizontal, coronal, and oblique. Before 

 cutting, photographs or tracings of the lesions, or both, were 

 made. 



EeSULTS OBTAINED. 



Degenerated fibres were ascertained to exist in the following 

 tracts and fibres : — 



1. Association Fibres. — In the first instance short association 

 fibres connecting the removed area with adjacent convolutions 

 or portions of cortex were found degenerated. But, in addition, 

 lonQ-er association tracts were also found to present the same 

 chance. One of these was the mferior longitudinal fasciculus 

 conveying degenerated fibres into the occipital lobe (see d. £?, 

 figs. 3 and 4). The other conveyed similar fibres to the parietal 

 lobe — iMricto-temporal fasciculus. 



These results are confirmed by recent observations of Pusateri} 

 who found degenerations in these tracts after removal of portions 

 of Munk's auditory sphere in cats. 



It must, I think, therefore be unquestionably accepted that 

 the inferior longitudinal fasciculus is mainly, if not wholly, an 

 association link between the occipital and temporal lobes. This, 

 the usually accepted view, has recently been contested by 

 Flechsigr who regards it as a projection bundle, descending from 

 the occipital lobe. It has, however, on the other hand, received 

 confirmation from researches by Sachs ^ into degenerations 

 followins; softening of circumscribed areas of the cortex. 



2. Commissitml Fibres :—(a) Corpus ccdlosum. — In every case 

 degenerated fibres were traced over the ventricular cavity 

 towards the corpus callosum, across the posterior half of which 

 they passed to reach the opposite «ide (see cl. o, fig. 1). In 

 this commissure, they were found mostly to occupy the lower 

 half of the vertical section. Having gained the opposite side, 



1 Pusateri, E., " Contrib. alio studio del origine dell fasclo pedunc. di Turck 

 e del fascio long, infer," II Pisani, s. 141-154. 



- Flechsig, P., "Die Localisation d. geistigen Vorgange, insbesond. der Sinnes- 

 Empfindimgen d. Menschen," Leipz., 1896. 



■' Sachs, H., "Ueber Flechsig's Verstand-Centren," Archiv. /. Mik. Aiiaf., 

 B. 48, pp. 550-572. 



