R. H. Whitehead 30% 
seen running ventralward on each side of the aorta. The latter grow 
rapidly, so that in the pig of 16 to 18 mm. there are chains of ganglia 
of considerable size lying between the adrenal and the aorta. Other 
ganglia lie immediately dorsal to the adrenal. From these ganglia 
nerve fibres arise, and, accompanied by cells, run lateralward along the 
dorsal and ventral aspects of the adrenal. Particularly large nerves 
pass along the medial aspect of the adrenal, some of which lie squarely 
Fie. 4. Pig 8 mm. Leitz obj. 7, oc. 4. Ad., adrenal; Mes., mesentery; C. c., 
coelomic epithelium; G., glomerulus; W. ¢., tubules of Wolffian body. 
against it, and in some cases even transfix it near its periphery. These 
nerves are not numerous, and there seems to be no reason to regard them 
as anything but the nerves to adjacent anlages which come into close 
relationship with the adrenal en route to their destination. 
In the following successive stages the increase in size both of the 
adrenal and the ganglia is very rapid; so that in the pig of 25 mm. 
the space between the adrenal and the aorta is occupied to a great extent 
by the sympathetic ganglia, and the latter are separated from the ad- 
renal only by its capsule. 
