260 BEATRICE WHITESIDE 
tions similar to those in the axolotl, the sacci, however, being 
separate. In salamander, he found that the sacci extend also 
below the brain. 
In Rana the relations are especially complicated, and accord- 
ingly were explained much later. Here the ductus leads from 
the sacculus into the cranial cavity, where it expands into a large 
saccus. In contrast to the condition in the Urodela, this organ 
is not confined to the cranial cavity, but extends in the verte- 
bral canal as far as the seventh vertebra, and sends out processes 
which come to lie on the spinal ganglia. I have given a detailed 
account of the whole organ in the first part of this paper. 
The different parts of the saccus endolymphaticus in Rana 
were discovered separately. The calcareous sacs on the spinal 
ganglia were necessarily the first to attract attention on account 
of their conspicuous position. They were found by Blasius in 
1681. Hasse (’73) discovered a chalky mass in the cavum cranii, 
which he identified as the sacci endolymphatici. Finally Cogegi 
(90) proved that the sacs on the spinal ganglia are outgrowths 
from the main stem of the saccus. 
In most of the Anura, examined in regard to this organ, the 
relations are similar. Sterzi (’99) described the saccus in Rana 
temporaria, ,Rana esculenta, Bufo vulgaris, Bufo viridis, and 
Hyla arborea. In both species of Rana he found the above- 
described expansion of the organ. In Bufo and Hyla there is 
only a slight deviation, in so far as the processes of the spinal 
part merely penetrate into the intervertebral foramina, but do 
not extend beyond these apertures. Coggi (’90) states that 
Discoglossus pictus and Bombinator igneus do not possess a 
spinal part of the saccus endolymphaticus. He does not describe 
the cranial part. Rex (’93) also examined Bombinator igneus. 
In this animal he found a thin vascular membrane lying on the 
roof of the fourth ventricle. This structure he takes for the 
degenerated saccus. In Pelobates, this author found the same 
expansion of the saccus as is known in Bufo. 
In the Reptilia the ductus endolymphaticus is found in its 
typical development. The saccus, however, is very small, and 
contains lime in the embryo only. Carus (’45), who was the 
