200 
J. BEARD. 
very evident (figs. 21, 24, 46, 51), I confess I see no conve- 
nience in the use of a name to which doubtful morphological 
characteristics are attached. 
We are now met by the question, Assuming that the ganglia 
arise as outgrowths of the neural ridge, what is the ultimate 
origin of the structure, and are the ganglia first visible in the 
neural-ridge stage ? 
The foregoing researches give the answer to this question, 
and in anything like a complete and correct form they are the 
first researches which can lay claim to decide the question. Six 
years ago Sagemehl (No. 56), in a prize research, published 
observations which he believed, and apparently the judges of 
the competition also, to be a solution of the problem, so far as 
the spinal ganglia are concerned. How little claim his 
researches have to pass as a last word on the origin of the 
ganglia will be evident to the reader of this paper, and if he 
will take the additional trouble to compare the numerous 
figures I have given here of Elasmobranchii and the Chick 
with the nineteen figures of Sagemehl’s work, he will, I think, 
admit the correctness of my conclusion, that Sagemehl never 
saw any of the earliest stages of the formation of spinal ganglia. 
Except for Marshall’s and Onodi’s researches on the cranial 
ganglia of the Chick, this remark applies to all the observa- 
tions of various investigators of the development of cranial 
and spinal ganglia. His (No. 29) has also seen, but only 
partially interpreted in a correct sense, some of the earliest 
stages in the cranial nerves of the Chick. As His’s Zwischen- 
rinne theory was one of the earliest on the development of 
cranial nerves, we can at once consider his claims to having 
furnished the solution to the above question in the wider sense 
of the origin of the ganglia Anlagen. Remak’s (No. 54) 
older observations, originally supported by Balfour and Foster, 
may be here passed over, for no one now believes that the 
ganglia arise as differentiations of the “ protovertebrae.” And 
the same also holds for Hensen’s conclusions (No. 24), which 
are more of a theoretical nature than results of actual investi- 
gation ; still, as I shall elsewhere show, there is an element of 
