466 AXATOinCAL TECHNOLOGY. 



what esaecfTerated in the figure, and the Crura olfactoria (Cr. ol.) should differ less in form 

 and in their distance from the mi^son. 



The FF. olfactoria [F. ol.) appear as little more than shallow furrows. 



On account of the foreshortening of the ventral aspect, the line of separation of the 

 Portio prominens (Ft. p.) and the Pt. depressa (Pt. d.) is indistinct. The hypocampal 

 lobule (LI. limp.) on each side has been flattened by pressure, and is so represented. 



§ 1164. Fig. 6. — The caudal aspect of the prosencephalon, with part of the dien- 

 cephalon. From Prep. 293, an adult 5 ; x 1. 



The diencephalou has been transected so as to leave a concave surface which, at the 

 meson, is close to the caudal border of the medicommissura {mcs.), but rises at the sides so 

 as to coincide nearly with the caudal surface of the prosencephalon. 



The postcommissura has been removed, and the slender transverse band {Cs. h.) just 

 ventrad of the splenium {sp.) is the Commissura habenarum. Had the postcommis- 

 sura been left, the intervening space wovdd be a foramen, Fm. conarii. 



The shallow depression of the ventricaudal surface of each hemisphere just laterad of 

 the splenium represents the area of contact of the opticus. 



The cerebral fissures are markedly unsymmetrical, and thus in contrast with those of 

 Fig. 5. The right postrhinalis (F. prh.) is the longer, and the right postsylviana (F. ps.) 

 joins the supersylviana, although the place of union does not appear in the figure. On 

 the contrary, by reason of the perspective, it seems to be joined by the F. medilateralis 

 {F. ml.). 



The hypocampal lobules {LI. hypocampce) have their proper rounded form in this 

 preparation. 



Part of the diacoelia {dc.) appears dorsad of the medicommissura, and part on its ven- 

 tral side (Fig. 133). In man, the commissure is smaller and the ccelia correspondingly 

 more extensive. On account of the removal of the hypophysis and infundibulum, the dia- 

 coelia opens freely at the Fm. infundibuli {Fm. inf.). 



§ 1165. Fig. 7. — The dorsal aspect of the diencephalon and mesencephalon. 

 From Prep's 397 and 494, adult ? , 433, a nearly adult 2 , and 506 ; x 3. 



The principal features of this figure were drawn from Prep. 506. The preparation was 

 made by lifting the caudal ends of the hemispheres and gradually separating them, with 

 the callosum, fornix and velum, from the subjacent parts. The epencephalou and meten- 

 cephalon were then removed by a transection just caudad of the postoptici. 



The valvula (ot.) is drawn as it appeared in Prep 494, after inflation by blowing air 

 from the diacoelia through the mesocoelia or iter. 



The Commissura habenarum {Cs. h.) is really more distinct in Prep. 397 than appears 

 in the figure. The habenae (//.), their sulci (81. h.) and the lines of reflection of the 

 endyma are taken from Prep. 423, and their distinctness is not exaggerated in the figure ; 

 see Fig. 133. 



The complete roof of the diacoelia, the diatela {dtl.), is shown in Fig. 10. 



As compared with the homologous parts in man, the feline postoptici (7W7).") and geni- 

 culata (pgn. and prgn.) sltb larger, while the thalami proper (^A.) seem to be only the 

 mesal continuations of the prccgeniculata {prgn.), and to lack altogether the pulvinar or 

 " posterior tubercle " of man. 



§ 1166. Fig. 8.— The caudal aspect of the mesencephalon, with parts of the 

 adjoining regions. From Prep. 500 ; x 1. 



The plane of transection coincides nearly with the caudal surface of the postoptici 

 {pop), and has divided the pons {pn.) a little caudad of its middle. The valvula {vv.) was 



