showed that the fore-brain roof in young and adult Teleostei was 
composed of an epithelial pallium. He considered therefore that the 
nervous structures of the fore-brain in Teleostei were represented 
by thick solid basal structures, homologues of corpora striata. The 
facts RABL-RÜCKHARD recorded are not open to doubt; indeed, they 
have been confirmed and extended to other forms by AHLBORN, WALD- 
SCHMIDT, GORONOWITSCH, EDINGER and others. 
AHLBORN !) demonstrated such an epithelial pallium in Petromyzon, 
WALDpScHMipT ?) in Polypterus, GORONOWITSCH *) in Acipenser and 
Amia, and myself *) in Lepidosteus. 
The explanation which RABL-RÜCkKHARD gave of the ee 
pallium is rather an ambiguous one. Our author looks upon this 
structure as an organ of the future — Zukunftsorgan —, asa 
layer of cells, which at one time or other is destined to play an im- 
portant part in developing nervous structures (even in the future 
races or higher evolutions of man!), and he also speaks of it in Te- 
leostei as showing reduced conditions. It is true that I have failed 
to gather that our author considers this part of the brain as a dege- 
neration in the group of Teleostei. Be this as it may, WIEDERSHEIM 
in the second edition of his „Grundriß der vergleichenden Anatomie“ 
expresses himself more decidedly in speaking of the pallium of the 
Ganoidei. 
The passage runs’): „Im Hirnmantel, welcher bei Selachiern fast 
in seiner ganzen Ausdehnung aus Nervenmasse besteht, sind bei den 
Ganoiden regressive Veränderungen vor sich gegangen, so daß er 
hier, wie wir auch bei den Cyclostomen konstatieren konnten, nur 
aus epithelialen Gebilden und membranösen Hüllmassen besteht.“ 
EDINGER, in the memoir already mentioned endeavoured to trace 
die vergleichende Anatomie des Gehirns, I. Das Vorderhirn“. Abhandl. 
d. SENCKENBERG'schen Nat. Gesell, Frankfurt a.|M. 1888, the reader will 
find most of what is known on this question. 
1) Autporn, F., Unters. über d. Gehirn der Petromyzonten, in 
Zeitschr. f. wiss. Zool. Bd. XX XIX, 1883. 
2) Watpscumint, J., Beiträge zur Anatomie des Centralnervensystems 
etc. von Polypterus bichir. Anat. Anz. II, 1887. 
3) Goronowirscu, N., Das Gehirn und die Cranialnerven von Aci- 
penser ruthenus. Morph. Jahrb. Bd. XIII. 
4) Bearp, On the early development of Lepidosteus osseus. Proc. 
Roy. Soc. London, 1889. 
5) WIEDERSHEIM, R., Grundriß der vergleichenden Anatomie der 
Wirbeltiere, 2. Auflage 1888, p. 153. 
