125 
Nachdruck verboten. 
Prof. RABL and the mode of development of the Vertebrate 
peripheral nervous system. 
By J. BEarv, Marine Station, Dunbar, Scotland. 
In a recent memoir entitled „Theorie des Mesoderms“ !) Prof. 
Ragı devotes about a page (p. 223—224) to the consideration of my 
recent researches on the above question ?). My reply could have been 
postponed until the publication of Part II of my results, but for one 
eircumstance. 
Not content with the assertion that my statements contradict the 
facts, RaBr challenges me to a demonstration of the sections which 
support my views at one of the next meetings of the ,,Anatomische 
Gesellschaft“, and he proposes to exhibit his own preparations which 
have only told him the things which BaLrour and a host of others 
already knew. To this challenge a reply of some sort must be made, 
for in the eyes of many silence would mean the revocation of my 
conclusions. 
In the first place I must say that I do not believe the matter is 
one which can be satisfactorily settled by such a hasty demonstration. 
I do not know who would be the judge, or how many and which compe- 
tent embryologists would examine the preparations. A further con- 
dition of Ragr’s is also a difficulty, viz. that each observer should 
be at liberty to move the preparations at will, for our author con- 
siders that an accidental „Riss“ in the preparation might be held by 
me to prove my contentions. As I have almost always used high 
powers, such as Zeiss F. in order to make sure of my facts, I fancy 
the use of such objectives at a demonstration, and under Rast’s 
conditions, might give rise to difficulties. 
1) Morph. Jahrbuch, Bd. XV, p. 113—252. 
2) Bearp, J., Morphological Studies No. 2. — The development of 
the peripheral nervous system in Vertebrates. Part. I. Quart. Journ, 
Microse. Sci. Vol. XXIX. 
