TRANSACTIONS OP SECTION D. 477 



to bird relationships. I have already (6) brought forward strong circumstantial 

 evidence to shov? that Apteryx is a Ralline bird, and not a Ratite. 



Consequently, apart from its academic interest, the hypothesis may have a 

 practical application. 



7. The Morphology of the Telencephalon of Spinax as a Type of Elasmo- 

 branch Fore Brain. By J. Stuart Thomson, M.S'c, Ph.D. 



The following gray masses or functional areas have been recognised in the 

 fore brain of Spinax : {a) Area olfactoria medialis in the rostral wall and in the 

 median part of the anterior portions of the lateral lobes; (b) Area olfactoria 

 lateralis in the lateral part of the more anterior portions of the lateral lobes ; 

 (c) Hypostriatum (Catois) or Area super ficialis basalis (Johnston) occupying the 

 greater part of the length of the telencephalon in a latero-ventral and medio- 

 ventral position; (rf) Nucleus medialis septi continuous ventrally with the last 

 area mentioned, and occupying a position internal to the downwardly directed 

 spurs of the lateral ventricles; (e) Primordium hippocampi on the dorsal sur- 

 face ; (/) precommissural or paraterminal body, a ventral extension of the 

 Primordium hippocampi; [g) Primordium pallii somatici, a correlation area 

 cccupying a lateral position in the walls of the prsethalamus or telencephalon 

 medium; (A) A^ucleus praopticus, an area disj)osed round the prseoptic recess. 



The following fibre-tracts have been located : (1) Tractus olfactorfiis later- 

 alis and Tractus olfactorius medialis ; (2) Tractus olfacto-corticalis lateralis 

 rectus; (3) Tractus olfacto-corticalis medio dorsalis ; (4) Tractus olfacto-corticalis 

 septi or Tractus cortico-medialis of Botazzi and Kappers ; (5) Tractus olfacto- 

 hypothalamicus; (6) Tractus pallii; (7) Tractus hippocampi; (8) Commissura 

 pallii posterior; (9) a tract which may be the fornix of authors, but which 

 does not agree in the distribution of the fibres ; (10) Tractus tcenioe. (Edinger) ; 

 (11) Tractus thalamo-corticalis. 



The author has not obtained any satisfactory or conclusive evidence of the 

 existence of a tract which might be correctly termed the corpus callosum. 



The paper was illustrated by fifty drawings showing the gray masses and 

 fibre-tracts noted in the preceding paragraphs. 



8. The Metamorphosis of Bilharzia, with Deinonslralion of Specimens. 

 By Lieut. -Colonel E. T. Leipeb, R.A.M.C. 



