311 



cerebellar crest. These facts furnish abundant evidence that the Lobus 

 trigemini of Gokonowitsch is a part of the tuberculum acusticum, an 

 interpretation which Kingsbury (8) has suggested from their general 

 appearance in ordinary preparations. Kingsbury has also pointed out 

 the non-identity of the L. trigemini of Mayser in teleosts and of Go- 

 konowitsch in Acipenser, a distinction which the facts in the present 

 paper further emphasize. The Lobus trigemini in Acipenser is the 

 same as the structure of that name in sharks. It has no relation with 

 the trigeminus nerve, but only with the lateral line nerve. I therefore 

 propose that it be known as the L. lineae lateralis." 



I am at a loss to know how Allis could refer (p. 148) to this 

 statement as evidence that the two lateral line VII roots in Acipenser 

 arise from two distinct centers. The opposite is what was stated. 

 Not only is the so-called lobus trigemini "a partially isolated portion 

 of the tuberculum acusticum", but the acusticum root of the lat- 

 eral line Vn sends its fibres into both! 



Finally, the statement of Wiedersheim that the lateral line organs 

 pass through a stage in their development in which they resemble end 

 buds is in part responsible for Allis' attitude. That statement was 

 made without citation of authority or of personal investigation ; it has 

 never received confirmation, is inconsistent with the fundamental difier- 

 ences between these organs clearly set forth by Merkel (10), is mis- 

 leading in the extreme and should not be repeated until it has been 

 confirmed by special investigation. It is impossible that these organs 

 should ever resemble one another in any more than a superficial way. 



The questions at issue have been fully discussed in a paper (5) 

 on the brain of Acipenser published while Allis' paper was in press. 

 That paper contained the first discussion of the nature of the special 

 cutaneous centers based upon the study of their minute structure by 

 modern methods. It may be added that the study of the brain of 

 Petromyzon substantiates in every particular the conclusions arrived 

 at in the study of the brain of Acipenser. The Petromyzon paper (6) 

 and another paper (7) on the more general results of recent brain 

 studies will be published before the present note appears, and are re- 

 ferred to here in order that they may be consulted in this connection. 



It is worth while to emphasize again the importance, already 

 pointed out by Strong and Herrick, of a study of the nerve centers 

 as well as the distribution of the nerve rami, in seeking the solution 

 of problems in the cranial nerves. Had Allis thoroughly acquainted 

 himself with the structures in the medulla concerned in the innervation 

 of the ampullae, he could not have entertained for a moment the hypo- 



