324 DR. GADOW ON THE ANATOMY OF PTEROCLES. [ Mar. 21, 
centim. The second loop is nearly double the length of the first, 
and has its apex doubled up into an irregular knot, as is characteristic 
of the Gallinacei proper. The third loop is of about the same length 
but straighter. ‘The fourth loop is almost three times as long as 
the duodenal one ; it is stowed away in the most ventral and lowest 
part of the abdominal cavity, between the gizzard and the vent; 
throughout its whole length it is accompanied by the two ceca, 
which are closely attached to this loop, as they are supplied by the 
same branch of the mesenteric artery. The rectal part of the intes- 
tinal tract is slightly wider than the ileum and the duodenum. 
The ceca (see fig. 4) are extremely well developed in Pterocles, 
being 16 centim. long, and are inserted at a distance of 15 centim. 
from the anus, They are very wide and have very thin walls ; their 
Fig. 4. 
a, Cxcea of Pterocles arenarius; b, Ceca of Syrrhaptes paradoxus (after Brandt). 
immer lining forms about 6 longitudinal slightly elevated folds. 
(Prof. Parker says that the czeca of the Sand-Grouse have 12 longi- 
tudinal folds, not 7 as have the Ptarmigans.) 
The ceca of Syrrhaptes, according to Brandt, are yery wide and 
long too, but differ from these organs of Pterocles in the shape of 
their terminal parts, as shown in fig. 4. 
The liver of Pterocles I found to consist of two principal lobes— 
the right lobe being about three times larger than the left one, 
which exhibits on its inner side a small Spigelian lobe. The sharp 
