1132 General Notes. 
specimens soon mould; if covered by muslin the sand in a short 
time becomes too dry and the specimens, if they emerge at all, are 
apt to do so in a crippled condition. I have obviated these diffi- 
culties by boring a hole in the bottom of the jelly-glass or fruit-jar 
and setting it in a flower-pot saucer. By pouring a little water 
into the saucer from time to time, the sand in the jar can be kept 
moistened and the excessive wetting caused by pouring water upon 
the sand avoided. The holes in the glass are bored by means of 
the end of a broken rat-tail file wet with turpentine. 
Other forms of new apparatus are in use, but they are not suffi- 
ciently perfected to warrant description at this time.— John Henry 
tock. 
EMBRYOLOGY.' 
EVELOPMENT OF THE PERIPHERAL NERVOUS SYSTEM OF 
VERTEBRATES.—Dr. Beard? continues his important studies on 
this subject, which is just now interesting some of the most distin- 
guished of living students of the general ontogeny of the verte- 
brates. His results as to the origin of the ganglia of the posterior 
sensory roots of the spinal nerves, and of the sympathetic system, 
are startling and unexpected. His discoveries may also be rank 
as fundamental, and amongst the greatest of recent times, as regard 
their consequences. The following résumé of his conclusions 1s 
given in his own words :— | 
“The spinal ganglia of vertebrates are formed as differentiations 
of the inner layers of the epiblast just outside the limits of the 
neural plate. As the result of the cutting out from the epiblast of 
these ganglionic elements an appearance is presented by the epiblast 
which is left, to which. Professor His gave the name of ‘ Zwis- 
chenstrang.’ This has no share in the formation of the ganglia. 
The ‘ Zwischenrisme’ of His has no existence, but certain portions 
of the cranial ganglia, called here neural ganglia, aré develo 
from the epiblast before closure of the neural tube, in exactly th 
same way as the spinal ganglia. These portions of cranial ganglia 
are more or less homologous with spinal ganglia, possibly only with 
the sympathetic portion of the spinal ganglia ‘ Anlagen) After 
separation from the epiblast, the ve i cranial ganglia and the 
