142 The Cardiac Glands of Mammals 
thelium is separated from the fundus glands by a narrow row of glands 
called by Klincowstrém, pyloric glands, but probably correctly inter- 
preted by Oppel as cardiac glands. The final section of the stomach 
is lined by stratified epithelium and is without glands. 
An examination of the schemes presented in the foregoing pages re- 
veals a number of interesting facts, to some of which attention has 
been already directed by Oppel and others. 
The first fact that strikes one 
is that in all these orders except 
the Ungulata, individuals exist, 
the stomachs of which closely re- 
semble in structure those of 
many existing Carnivora, Insec- 
tivora and Primates. 
There are good reasons for 
supposing that these stomachs 
represent a persistent primitive 
condition. They correspond 
closely in the relations of the 
different gland areas with the 
stomachs of lower vertebrates. 
Furthermore specialization in 
the stomach of mammals is ac- 
companied by suppression of ex- 
isting elements (glands, etc.) as 
well as by increasing complexity 
of structure, and it is therefore 
unlikely that primitive condi- 
tions would be simulated in a 
stomach that has been derived 
Fria. 15. Stomachs of: A, Dasypus; B, Brady- sebatcualy, By Bes en Ts Mei 
pus (both modified from K lincowstrém). retrogressive processes occurring 
in an organ already highly specialized. 
Moreover, in the Ungulata, no existing member of which exhibits a 
perfectly simple stomach, the nearest approach to this is found in those 
animals (the pigs in the Artiodactyla, and the tapirs in the Perissodac- 
tyla) which have been conservative in other respects, as for example, 
dentition and foot structure. 
The obvious inference from these facts is that the specialized stom- 
achs found in many mammals belonging to different orders, have been 
differentiated at a comparatively late period and entirely within the 
