4. Emil Goetsch. 
from animal to animal of the same species, and in a single animal 
varies with the degree of extension of the membrane upon which it 
rests. Only the more pronounced differences in these respects may 
therefore be interpreted with caution from the standpoint of special- 
ization. 
It was apparent from the outset that very little help in interpret- 
ing the cesophageal glands of mammals could be obtained from the 
consideration of these structures in lower vertebrates, because glands 
occur in reptiles only in the form of imperfect crypts in certain tur- 
tles, and the so-called cesophageal glands of certain batrachia are, . 
according to Bensley (00), in reality gastric glands. 
Meruops or Strupy. 
One difficulty that at once presents itself in studies on the cesoph- 
agus is that of determining the point of transition of the pharynx 
into the cesophagus. In animals like the dog, where there is a trans- 
verse fold of the mucous membrane, corresponding in its posi- 
tion to the lower border of the cricoid cartilage, and to an actual 
change in structure of the mucous membrane, this is relatively easy, 
but in the majority of cases no such superficial line of demarcation 
exists, and the point of transition must be more or less arbitrarily 
established. In the descriptions which follow, the lower border of 
the cricoid cartilage has been taken as the point where the pharynx 
passes into the cesophagus. In his recent article on the cesophageal 
glands Haane (05) places the point of transition somewhat higher, 
at the level of the corniculate cartilage, but designates the portion 
of the tube included between this point and the lower level of the 
ericoid cartilage in the dog as “Csophagus-vorraum.” In order to 
include the doubtful region so designated by Haane, sections from 
this region have been studied in each mammal examined, but struc- 
tures occurring above the distal margin of the cricoid cartilage have 
been referred to the pharynx, those below to the cesophagus. 
In the case of the smaller mammals the entire cesophagus was 
fixed, in the larger mammals, where this was out of the question, 
a strip was taken including the whole length of the esophagus. 
For fixation, Zenker’s fluid was employed, Bensley’s alcohol- 
