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J. BEAKD. 
derived the cranial ganglia from the epiblastic thickenings 
which form the lateral sense organs, and the main roots of the 
nerves from the inner epiblast connecting this thickening with 
the neural plate. This latter conclusion, which I formerly 
supported, is wrong. 
Onodi (No. 51) extended Marshall’s (No. 46) description of 
the origin of the cranial ganglia in the Chick from the angle 
between the epiblast and the neural plate, in that he stated 
that the epiblast outside this also shares in the formation. 
Neither Onodi nor Marshall distinctly say whether they regard 
this portion of epiblast as part of the central nervous system 
or not. And, as we have seen for the cranial and spinal 
ganglia of other forms, they supported Balfour’s views. 
In a note which I quoted in the introduction, van Wijhe 
(No. 61) mentions that the olfactory nerve arises from an epi- 
blastic differentiation at the lips of the anterior neuropore. 
The present research, taken in connection with my former 
paper on the branchial sense organs, shows that the sensory 
nerve-elements of the whole of the peripheral nervous system 
arise as epiblastic differentiations independently of the central 
nervous system. 
VII. The Relations of Cranial to Spinal Ganglia and 
OF TIIE “ SEITENORGANE ” OF ANNELIDS TO THE SENSE 
Organs of Vertebrates. 
It is far from my intention to enter here into the discussion 
of morphological questions. My contribution to recent con- 
troversy may fitly find a place in a special paper in which I 
intend to analyse the recent critical studies of Professors 
Gegenbaur and His on Vertebrate morphology, and especially 
on the nervous system. 
But still, the conclusions to which Froriep and I arrived at 
regarding the fundamental differences which obtain between 
the head and trunk regions of Vertebrates may be here 
slightly reviewed, and, so far as I am concerned, revised in the 
light of the facts recorded in the preceding pages. Gegenbaur 
