127 
transitory or larval nervous apparatus in all the oviparous Ichthy- 
opsida I examined !). The existence and fate of this larval nervous 
apparatus are easily verified, nay even demonstrated. I maintain, more- 
over, that my description of the development of the peripheral nervous 
system was not only new but true. I found it first in the cranial 
ganglia of the Chick, and afterwards confirmed my results in members 
of all classes of the Vertebrata. In ascribing an independent epi- 
blastic origin to the cranial ganglia of the Chick I was confirming 
Onopri’s results: for that animal I have on my side the unbiased testi- 
mony of an observer who, so far as I know, belongs neither to the 
Amphioxus nor the Annelid school. At any rate he has not cited his 
results as evidence on either the one side or the other. 
Prof. RaBL may dismiss any idea that I wish to beat a retreat. 
Far from it. I will make a simple proposition. Chick embryos are 
easily obtainable; let Prof. RABL investigate the development of the cra- 
nial ganglia of this animal, and let him publish his researches with 
figures, showing that they arise as outgrowths of the central nervous 
system and not as Onopi, myself, and partly MARSHALL have de- 
scribed their origin. 
I challenge any embryologist to maintain the former view as the 
result of the study of decent preparations of Chick embryos in the 
stages I have mentioned and figured in my memoir. I will even under- 
take to lend Prof. Rasy the preparations for this comparatively easy 
task, if he should desire it. 
Perhaps Prof. Rani will admit the facts to be as Oxopı and I 
described them for the Chick. If so, will he maintain that the cranial 
ganglia of other forms can arise in any other way? I think not, that 
would need a bigger hypothesis than any Rapti has yet enunciated. 
If his results contradict mine on that point, then I am quite ready to 
uphold my thesis by a demonstration of Chick preparations, for the facts 
are very readily made out in such preparations, and in the case of 
the cranial ganglia of the Chick a careful observer can make no 
mistake. 
After Rast has defined his position on this point, I shall be 
prepared to reconsider his proposals. 
RABL denies that there are any signs of cranial ganglia to be seen 
until some time after the separation of the central nervous system 
1) Bearp, J., The early development of Lepidosteus osseus. Proc, 
Roy. Soc. Lond. 1889, p. 116—118. 
