Johnston, Forebrain Vesicle in Vertebrates. 535 



to those already in the BI^A hecause they are necessary if the BISTA 

 is to be used in comparative neurology : vehini transversum, recessus 

 postopticus, recessus prseopticus to replace recessus opticus, and 

 paraphysis. The chief changes proposed consist in the shifting of 

 certain terms from the diencephalon to the telencephalon in accord- 

 ance with the new boundary laid down, and a more complete tabula- 

 tion of terms under the telencephalon in accordance with the results 

 of a genetic and functional analysis of that segment. The changes 

 are such that it will require very little effort for anatomists and 

 neurologists to adjust themselves to the usage proposed. The advan- 

 tages are that the tabulation and definitions proposed express 

 accurately the actual relationships, harmonizing the facts of ontogeny 

 and phylogeny with those of adult mammalian and human anatomy. 

 The aim is to adjust neurological terms to the needs of comparative 

 as well as human neurology and to avoid confusion arising from 

 apparent discrepancies between embryology and anatomy, betAveen 

 comparative and human anatomy. These discrepancies now require 

 much time and patient effort in explanations to students. A con- 

 stant effort is needed to revise our terms to bring them into accord 

 with the facts. Such is the object of the present suggestion. 



Note to Pages 4G4 and 5()C>. In a paper which has appeared since this 

 article went to press, Hatschek {Morph. Jahrb., vol. 39, 1909) reaches con- 

 clusions with regard to the anterior end of the head in cyclostouies almost 

 identical with my own. His Basilareclcc corresponds to my primitive optic 

 groove, his Basilarlipiw to my terminal ridge. He states that the anterior 

 pole of the craniate body is marked by the Hypophvsenecke, where the floor 

 of the neural tube and the roof of the archenteron end forward. I cannot 

 agree with Hatschek's statement (p. 519) beginning "Die Basilarlippe stellt 

 den primitiven Vorderwall des Medullarrohres dar." The Basilarlippe or 

 terminal ridge belongs without doubt to the floor of the neural tube and is 

 occupied by bundles of the ventral fiber decussations. 



