4 . ALBERT KUNTZ 
pated posterior to the cephalic region. In still others, only a 
portion of the neural tube in the posterior cephalic region was 
extirpated in an attempt to eliminate the nuclei of origin and 
the ganglia of the vagi. In a few instances two tadpoles from 
which a strip of tissue including the neural crests and the dorsal 
portion of the neural tube was cut were placed in contact with 
each other in such a manner that the cut surfaces of the neural 
tubes were approximated. ‘These tadpoles readily healed to- 
gether, thus preventing any regeneration of the dorsal portions 
of the neural tubes. In the other tadpoles which were operated 
in the same manner, the neural tube became closed dorsally, 
but neither the neural crests nor any considerable portion of the 
neural tube which was removed was regenerated. Among the 
tadpoles which survived the operation, those from which a strip 
of tissue including the neural crests and only the dorsal portion 
of the neural tube was cut lived a week or longer. Those in 
which the entire cerebrospinal nervous system was extirpated 
in the postcephalic region, as well as those in which an attempt 
was made to eliminate the vagi, failed to live longer than four 
or five days following operation. These were also retarded 
somewhat in their development; consequently, they represent 
a stage of development somewhat less advanced than their age 
indicates. 
THE GENETIC RELATIONSHIP OF THE SYMPATHETIC TO THE 
CEREBROSPINAL NERVOUS SYSTEM 
In his pioneer work on the development of the sympathetic 
nervous system, Remak (’47) advanced the theory that the 
cells which give rise to the sympathetic ganglia are differentiated ' 
in situ from mesodermal tissue. This theory was accepted by 
Goette as early as 1875 and still advocated by him at a much 
later date. Since Balfour (77) clearly pointed out that the 
sympathetic is derived from the cerebrospinal nervous system, 
investigators in this field, with few exceptions, have supported 
this view. The older theory of the mesodermal origin of the 
sympathetic nervous system was revived by Paterson (’90) 
and Fusari (92). Among the more recent investigators, few 
