352 
Transactions of the Royal Society of South Africa. 
plexus ; a second (SP) runs down 
connected to the solar plexus ; a tl 
I 
Fig. 6. — The Sympathetic system. I — IX 
= the spinal nerves ; A = Vagus (cranial 
nerve) ; CP = sympathetic curve to cardiac 
plexus ; E = loop (with no nerves of sympa- 
thetic chord ; SP = sympathetic nerve to 
solar plexus ; MP = symph. nerve to reno- 
genital plexus (?). 
knobs at a very early stage in the 
to the mesentery and is probably 
1 (MP) runs upwards to the tissues 
along the vertrebal column just 
beneath the kidneys and is pos- 
sibly connected to the renal-re- 
productive plexus. Besides these 
sympathetic nerves there is a ring 
(E) which encircles the innomi- 
nate artery without giving off any 
branches. 
Random Observations on Xeno- 
pus Tadpoles. The very young 
tadpoles are very much like those 
of frogs ; the colour is of the usual 
muddy, somewhat opaque grey 
and the tail is without the fins." 
They can, however, be distin- 
guished by the fact that the jaws 
are not horny; there are no ten- 
tacles. Later on as the young 
tadpole grows, its skin becomes 
clearer and finally quite trans- 
parent ; the head becomes flattened 
and the sides of the mouth grow 
forwards ; the tentacles are de- 
veloped on the protuberances at 
the sides of the mouth. The tail 
is well developed and its point, 
unlike that of other tadpoles with 
which I am acquainted, performs 
continuous vibratory movements 
which have nothing to do with 
locomotion. 
I have not been able to get 
Xenopus to deposit eggs in the 
laboratory, but I have managed 
to net very small larvae and have 
seen no trace of external gills. 
There is a delicate operculum 
which opens to the exterior by 
two lateral openings. The oper- 
culum never covers the fore-limbs 
as in the frog ; these limbs are 
seen as minute, white, opaque 
development. 
