Wilder.] 54:0 ^julv 15, 



are shown: The Fissura dorsimesalis {F. dms.), or " Posterior fissure ;" 

 the dorsilateral fissure {F. dl.) ; the Golumna dorsalis {dm. d.), and the 

 Clm. lateralis (,01m. I.) ; on the right side, the i^rincipal trunk of the N. 

 aceessorius {JS'. ad.), and the dorsal or sensory funiculi of the first spinal 

 nerve (iV". cv. 1.). 



As already stated, the fissures of the hemispheres are diiferently repre- 

 sented upon the two sides. ^ The combination of the two kinds of fissural 

 arrangement in a single figure serves to illustrate the extent of the lateral 

 variation and compensation to which attention was called by me in 1873 

 (10, 232). 



The postsylvian and supersylvian {FF. ps. and s.) are represented as 

 united upon the left side, but separated on the other. The junction is 

 more common, but the separation is sometimes complete. The case is 

 somewhat similar with the lateralis and medilateralis {FF. I. a.nd ml.). 

 The ansate fissure {F. an.) presents itself in so many forms that it is diffi- 

 cult to determine its normal condition and connections. It is usually 

 joined with either the lateralis or the eoronalis or both ; when separate, it 

 often is triradiate ; but occasionally, as in prep. 294, on the left side, it 

 forms a nearly straight fissure at right angles with the lateralis and eoro- 

 nalis, and wholly independent of them both. This condition is repre- 

 sented on the right side of fig. 1. This fissure demands fuller investiga- 

 tion, especially with reference to its representation in the human brain. 



So far as I know, the following junctions of fissures which, on some 

 grounds, may be regarded as fissural integers, are constant in the cat : Of 

 the rMiial {rJi.) with postrhiiial {prh.), and of the sylvian (s.), with the 

 point of their union ; of the superorbital {so. ), with the rhinal ; of the 

 eallosal (d.), with the hypocampal (hinp).), and with the preradical {prrd.), 

 when it exists. 



The following junctions are common : Of the diagonal (dg.), with the 

 anterior {a.) ; of the postsylvian {ps.), with the supersylvian {ss.) ; of the 

 medilateral (ml.), with the lunate {In.), and with the lateral (1.), or the eon- 

 finis {cf.) ; of the marginal {mr.), with the postmarginal {pmr.) ; and of 

 the ansate {an.), with the lateral or coronal {cor.), or both. 



The junction of the cruciate {F. cr.), with the splenial (F. sp.), which 

 Guillot has seen once, Krueg twice (Krueg, 2, 620), and Pansch {1), three 

 times out of fourteen, has been observed by me on only four of the many 

 hemispheres examined. I have never seen a union of the splenial with the 

 postrhinal { prh. ) . 



I have never observed the union of the anterior and posterior fissures to 

 form the "first or lowest arched fissure" of the Canidaj. On the other 

 hand, as stated by Krueg (.f,613), and by myself (11,329), this union some- 

 times fails with domestic dogs ; hence, in this as in many other respects, 

 the cat presents less tendency to vary. 



A junction of two fissures is usually marked by a less depth of the com- 

 pound fissure at that point, constituting a concealed "transition convolu- 

 tion " or " pli de passage," which may be seen by separating the sides or 

 by slicing off the cortex. 



