CuRRAN, A New Association Fiber Tract. 655 



other white matter as it enters the frontal lobe, there is little to be 

 said beyond the fact that it is soon lost in intercrossing with the 

 internal and external capsules, corona radiata, etc. It is distributed 

 largely to the external side of the frontal lobe, and to Broca's area. 

 The posterior part of the fasciculus (from the posterior end of the 

 lenticular nucleus to the occipital pole) has, in immediate relation- 

 ship with it, fibers from the superior temporal convolution. These 

 are to be seen in Fig. 2 (F. o. t.) and in Fig. 3 streaming back- 

 ward from the white substance of the superior temporal lobe. They 

 constitute a broad flat band leaving the sup. temp, convolution by 

 way of the posterior surface of its medullary substance throughout 

 its whole length. They are the first long associating fibers met after 

 removing the short ones which connect the superior with the middle 

 convolution. I do not identify it with the fasc. longitudinalis infr., 

 for this is shown in many of the text-books lower do^vn, and for 

 descriptive purpose in this paper it is referred to as the fasciculus 

 occipito-temporalis. In Fig. 1 it has been removed to show the fasc. 

 occ. front, inf. passing under the fasc. arcuatus. The fibers of the 

 fasc. occ. temp, run for a short distance two or three centimetres 

 before mixing with the fasc. occ. front, infr. and the optic radiation. 

 On the outer side, and lower down, not shown in any of the pictures, 

 lies the inferior longitudinal bundle, some of tlie fibers of which far 

 back in the occipital lobe intercross with the fasciculus. Lying imme- 

 diately over this fan-like spreading of the fasciculus occipito-frontalis 

 inferior and the other fibers running alx)ve it in the same direction, 

 which have already been described and are shown in the pictures, 

 are the arcuate bundles and the fasc. trans, occ. (F. trans. 0., Fig. 

 2). The former, as previously pointed out, are joined by very 

 large bundles of the corpus callosum on their way to the cortex. 

 They make up the greater part of the medullary substance of the 

 superior and middle temp, convolutions and much of the inferior. 

 In order to get into the sup. and mid. temp, convolutions the fasc. 

 arcuatus (F. arc.^, Fig. 1) divides into anterior (F. arc.^. Fig. 1) 

 and posterior (F. arc.^ and F. arc.'*. Fig. 1) branches. Besides these 

 two branches a number of fibers continue directly backward and end 

 in the parietal lobe about the angular gyrus and the superior end of 



