204 
J. BEARD. 
matters of agreement as Professor His supposes, one may 
quote it again with the request to Professor His to furnish 
us with the evidence in which he bases his opinions on the 
origin of the ganglia from the Zwischenstraug and Zwischen- 
riune, and of the olfactory and auditory organs from parts of 
the latter structure which l’emaiu open (No. 34, p. 417). 
These are questions of facts whose accuracy I challenge. Nor 
are they the only points of fact on which I (and many others) 
disagree with Professor His. Of that more elsewhere. 
The passage reads: “Bei genauerem Zusehen findet man 
eben, dass die Differenzen nicht in dem liegen, was der eiue 
und der andere Beobachtungskreis an thatsachlichen Befunden 
ergiebt, sondern in demjenigen, was die Yertreter der einen 
und der anderen Schule zwisclien die Zeilen zu lesen sich 
bemiihen. Nun sind aber die jiiugeren vergleichend rnorpho- 
logischen Schulen in der Lecture zwisclien den Zeilen iiberdie 
Maasen weitgegangen, und ich halte es fureine Pflicht, meineu 
Bedenken hiergegen offenen Ausdruck zu geben.” 
However it may be with the hypotheses, &c., one thing is 
certain, that some of Professor His’s most funda- 
mental facts are no facts at all, and we may not un- 
naturally ask whether the reproach intended for us 
younger morphologists does not partially recoil on 
Professor His himself? 
All other observers, excepting Spencer for the cranial 
ganglia of Amphibia, are agreed in referring the source of the 
posterior roots and ganglia to the neural ridge of Marshall, 
and nearly all agree with Balfour’s maxim of the origin of the 
latter structure as an outgrowth from the central nervous 
system. 
On p. 369 of the ‘Comparative Embryology’ of Balfour, 
vol. ii — a book which represents his latest views on the ques- 
tion — we read : “ All the nerves are outgrowths of the central 
nervous system;” and on p. 374, “The neural crest clearly 
belongs to the brain, from the fact of its remaining connected 
with the latter when the medullary tube separates from the 
external epiblast.” 
