Sl'iYOJVrMS AND REFERENCES. 471 



The special object of this figure is to show the hypocampal fissure {F. hmp.) in its 

 whole 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.), 

 BO as to become continuous with the callosalis (F. cl). The fasciola {fscD is wide and 

 devoid of denticulatioiis, but is crossed obliquely by a shallow furrow. In this [losition of 

 the preparation, the F. fimbriae (F. finb.) appears to be continuous with a short line pass- 

 ing 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. flmhrice, like the 

 callosalis, turns sharply dorso-caudad to terminate just cephalad of the splenium (Fig. 125). 



§ 1176. Fig. i8. — The right proccelia seen from the right or ectal side. From 

 Prep, im ; x 1. 



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 the praecornu 

 {preii.). The proplexus (prpx.) is slightly displaced, but the porta is hidden by the 

 portiplexus (ppx.). The medicornu {incu.) and the hypocampa (hmp.) are shown in sec- 

 tion, and the other parts will be readily recognized. The relative heights of the opticus 

 (op.) and the postopticus (pop.), 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 rhinoccelia (Pig. 10). 



§ 1177. Fig. 19. — The left praecornu and porta exposed from the left or ectal side. 

 From Prep. 495 ; x 1. 



This figure represents the other side of the same brain from which Pig. 18 was drawn. 

 The preparation was made in the same way, but in addition the proplexus and porti- 

 plexus were carefully snipped ofif so as to expose the porta. 



The porta (p.) is seen to open between the Columna 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 vrith the picture-plane. 



The membranes could not be shown well on so small a scale (see Pig. 123). In this 

 and in the previous figure, the fornix is seen to be continuous with the hemiseptum (Spt. 

 lu.) which forms part of the mesal waU of the prcecornu. 



§ 1178. Fig. 20. — Transection of the fornix with the crista. From Prep. 508 ; x 1. 

 The object of this figure is to showthe decided elevation formed by the crista (Crs. /.). 

 Only enough of the rest of the section is included to locate the crista. 



§ 1179. Other Figures of the Cat's Brain.— Since most published figures of the cat's 

 brain illustrate the fissures rather than the structure, they will be mentioned in connec- 

 tion with Fig. 124, 125, later in this chapter. 



SYNONYMS AND REFEEENCBS. 



§ 1180. The principal parts of the Amphibian Ibrain are enume- 

 rated in § 1058 and tabulated according to their segments in § 1069. 



Most of the parts of the Mammalian brain whicli are visible to 

 the unaided eye are named in § 1128 in the alphabetical order of 

 their abbreviations, and in § 1138 they are tabulated according to 



