208 J. B. JOHNSTON, 
In Acipenser the non-decussating fibres turn laterally, while in the 
region of the raphe caudal to the corpus interpedunculare are 
situated the fine-fibred bundles from the medulla (bundle x). I hope 
soon to investigate whether these are actual differences between eal 
brains of Acipenser and Petromyzon. 
OSBORN (88) in studying Cryptobranchus traced the bundles of 
MEYNERT to the corpus interpedunculare and a little beyond and 
refers to the fact that AHLBORN had traced them into the medulla. 
These are the only cases in which the bundles have been traced 
beyond the corpus interpedunculare, except in Acipenser (my pre- 
liminary papers ‘98a, b). 
GORONOWITSCH (89) describes the ganglion, superior com- 
missure, and the course of MEYNERT’'s bundles. He could follow 
the latter only to the proximal border of the ganglion interpedun- 
culare and could not make out the terminal relations described by 
MAYSER. The end nucleus of the bundles of MEYNERT appears in 
figs. 54—56, but is not lettered. 
BuRCKHARDT (91) says that in Triton and Ichihyophis the 
bundles of MEYNERT run from the ganglion habenulae to end in 
the base of the mid brain. 
EDINGER (92) gives the following description of the termination 
of these bundles in Selachians: “Die Hauptmasse [of the corpus 
interpedunculare] wird von dem im Corpus quer daher ziehenden und 
sich unter einander verflechtenden Fasern der Fasciculi retroflexi 
ausgemacht. Die einzelnen Ausläufer dieser Bündel verschränken 
sich, von rechts und links her kommend, so unter einander, dass es 
wahrscheinlich ist, dass sie sich unter einander verbinden. Wenn 
man beide Arme ausstreckt und die Finger der Hände dann in ein- 
ander faltet, dann hat man das Bild des hier geschilderten Systems. 
. Zwischen den Fasern liegen zahlreiche rundliche Körner und 
eine krümelig feinkörnige Substanz.” EDpINGER calls this group of 
cells the “Corpus interpedunculare” because he is not sure that it 
is a true ganglion. 
VAN GEHUCHTEN (’94) studied these bundles by the method of 
GOLGI in embryos of the trout. His description and figures of their 
origin from the cells in the ganglia habenulae agree closely with my 
own. I quote in full his description of the ending of the bundles 
in the corpus interpedunculare: “Arrivée à ce niveau, chaque fibre 
du faisceau de MEYNERT se coude horizontalement en dedans; elle 
se divise et se subdivise un grand nombre de fois pour s’entrelacer 
