292 
ginning at the 11 and only ending (in a partial contradiction) in 
the 15%. 
In the latter case1), departing from former denials that ganglion 
cells were ever proliferated from the neuroepithelium, or that the nerve 
in connection arose at all as described by me, Prof. Donen stated his 
inclination to admit “daß die Kopfganglien einen Zuwachs aus Ekto- 
dermzellen erhalten, daß aber diese Zellen (welchen ich ... den 
Namen Nebenganglien beilegen möchte) keinen Anteil an der Ver- 
sorgung der Schleimkanäle und Seitenlinie zu nehmen scheinen”. 
More recently this position of 1890 has been entirely abandoned, and 
in the latest „Studie”?) the origin, mode of growth etc. of these 
nerves of the sense organs, and of ganglionic and nerve-forming cells 
from the neuroepithelium are described in remarkably close agreement 
with my account written in the year 1885. 
In consideration of these contradictions and of the circumstance 
that Donrn’s previous antagonism (along with that of others who are 
also gradually adopting my standpoint) has tended to discredit my 
work, it was surprising to find that the only reference to my researches 
and to Dourn’s previous opposition was contained in the following 
lines : 
“Ich habe früher dieses Eingelagertsein des Nerven in das Ekto- 
derm als ein Durchwachsen der vom Ganglion ausgehenden Fasern 
durch das Epithel angesehen, wie es auch von BALFOUR geschah: die 
Kerne nahm ich als angelagerte Mesodermkerne in Anspruch und 
zweifelte so wenig an der Richtigkeit dieser Auffassung, daß ich sogar 
die von anderer Seite behauptete “Abspaltung” des Nerven vom Ekto- 
derm als eine nicht zu verstehende Ausdrucksweise ansah. Ebenso 
ging es mir mit der Faserbildung des Lateralis” *). 
It may be added that I read the latest “Studie” with feelings 
more of pleasure that at last the distinguished morphologist found 
himself able to confirm in the main, if also to extend, my work of 
1885, than of disappointment and chagrin that he had neglected to 
cite my paper and that in other directions he had anticipated to no 
small extent my unpublished work. 
The second portion of DoHrn’s work treats of the histogenesis of 
various nerves (not nerves of sense organs) and of ganglia and ganglion 
1) Dourn, A., Studien zur Urgeschichte etc., No. XV, p. 429. 
2) No. 17, pp. 256—281. 
3) Donen, Studie No. 17. Nervenfaser und Ganglienzelle. Mitteil. 
a. d. Zool. Station zu Neapel, Bd. 10, Hft. 2, p. 272. 
