34 JoUKNAl, <)!• C()MPAUATI\K NeITROLOGV. 



though certain cells suffer subdivision into nucleus-like 

 bodies or Deiters" corpuscles, but of this there is insufficient 

 evidence. In the cephalad part of the axial lobe there is a 

 special mass of proliferating cells. The multiplication here 

 is the same as that in the occipito-basal lobe — longitudinal 

 fission rather than the endogenous multiplication described 

 beyond by Mr. Turner in the corresponding region of birds. 



Miscellaneous Notes. — -The two commissural systems of 

 the habena are well shown, as is the connection with the 

 epiphysis. The latter is constructed obviously upon the 

 same plan as that of the lizard, and, in the present case at 

 least, is of moderately large size. This fact makes it the 

 more surprising that Stieda should have overlooked the 

 existence of a true epiphysis in the turtle. It is true that 

 the body is obscui^ed by the large plexus which envelops 

 it, but a glance at Fig. 7, Plate III, will show that the 

 nervous connection with the habena is complete, and the 

 neuro-epithelium of the tube is also very similar to that of 

 the lizard. The tubular organ is curved cephalad so as to 

 become somewhat sickle-shaped. The peduncle is hollow 

 throughout, and opens not into the third ventricle directly, 

 but into the canal connecting the optic ventricle with the 

 dorsal part of the third ventricle. 



The optic ventricle is large and its cornua extend far 

 laterad. The tectum opticum is very thick and has the 

 usual structure, except that in the median portion immedi- 

 ately above the ventricle and lying in the inner zone of 

 concentric cells there is an unusual development of the bal- 

 loon cells mentioned in the alligator. It is impossible to 

 trace any connection with the trigeminal fibres, however. 



In the thalamus the two large niduli, which in the alliga- 

 tor we ventvu'ed, for want of a better term, to call corpora 

 geniculata, are in this case very distinct, and lie some dis- 

 tance from the median line beneath the superior commissure 

 (Fig. 5, Corp. g.). The niduli themselves consist of large 

 fusiforni -cells in a horiiologous stroma of neuroglia. Sur^ 



