Wilder.] 55o [July 15, 



fornix and the callosum, is the mesal surface of the right half of the 

 8e]}tum ludclum {Spt. hi.) and is in contact with its 2Jlatetrop6 or lateral 

 homologue in the undissected brain. The thickness of the lateral laminae 

 constituting the septvim render the adjective lucidum wholly inapplicable. 



Fig. 17. — The mesal aspect of the right hemisphere, with the Lobus 

 olfactorius. From prep's 296 and 401. 



The caudal divisions of a half-brain were removed, and the thalamus 

 carefully excavated so as to leave i;ndisturbed tl\e fornix (f.) and the 

 fimbria (fmh.). In this respect, this figure may be compared with the 

 left half of fig. 14. 



The special object of this figure is to show the F. hypocam'pm {F. hmp.), 

 in its Avhole length at once. So great is the curvature of the parts that 

 this is possible only in a single position of the preparation in which the 

 meson is foreshortened. In general, this figure may be compared with 

 those given by Flower (13) of the rabbit and sheep. 



The dorsal end of the F. hypocampm is seen to turn sharply around the 

 splenium (sp.), so as to become continuous with the F. ccdlosalis {F. cl.). 

 The fasciola (fscl.), is wide, and devoid of denticulations, but is crossed 

 obliquely by a shallow furrow. In this position of the preparation, the 

 F. fimiricB {F.fmb.), appears to be continuous with a short line passing 

 cephalad to a point ventrad of the callosum ; in reality, however, this latter 

 line is only one of the markings of the ventral surface of the fornix, and 

 the F. fimbria, like the F. callosalis, turns sharply dorso-caudad to termi- 

 nate just cephalad of the splenium. 



Fig. 18. — The rigJit proccdia seen from the right or ectal side. From 

 prep. 495. 



The right half of the brain was removed in successive slices until what 

 remained was about 3 mm. thick. The remainder of the striatum was 

 then everted from l\i.e prcBcornu (prcu.). The p^^oplexus (prpx) is slightly 

 displaced, butthe^orto is hidden hj the portiplexics {ppx.). The medi- 

 cornu (tncu.), and the hypocampa {limp.), are shown in section, and the 

 other parts will be readily recognized. The relative heights of the 

 opticus (op.), and the postotpicus {ptop.) at a little distance from the 

 meson are well displayed. The short curved line at the cephalo-ventral 

 end of the proccelia represents the beginning of the passage to the rliino- 

 coelia. 



Fig. 19. — The left prmcornu andpo?'to exposed from the left or ectal 

 side. From prep. 495. 



This figure represents the other side of the same brain as that from 

 which Fig. 19 was drawn. The preparation was made in the same 

 way, but in addition the proplexus and portiplexus were carefully snipped 

 off so as to expose the porta. 



The porta, {p.) is seen to open between the Uolumnm fornicis {Clm.f.) and 

 the cephalic end of the thalamus {th.). The orifice would appear larger if 

 the preparation had been so placed as to leave its plane parallel with the 

 picture-plane. 



