60 
C. H. MARTIN AND MURIEL ROBERTSON. 
[from the facts mentioned below, that all these names — 
: Sa'enoloph us (Stein), Trypanosoma Eberthi (Kent), 
and Spirochaeta Eberthi (Liihe) must now lapse. 
2. Cjeca op Fowls. 
Before proceeding to the special part of the paper it will 
be necessary to give a short account of the caeca of the 
intestine of fowls, since it is this portion of the alimentary 
tract to which these parasites seem to be confined. 
According to Newton ( f Dictionary of Birds/ p. 18), ‘‘it 
is highly probable that originally all birds possessed caeca, 
and that according to the diet these were either further 
developed or reduced in size, or even lost ultimately/’ 
In the case of the fowl the caeca are two blind sacs, rather 
variable in size, arising at the proximal end of the rectum. 
As a general rule the two caeca are found in a distended 
conditon, and it would appear that almost the whole process 
i of faeces formation in the fowl takes place in these organs. 
In the early stages of this process the caeca are filled with 
a light yellowish, rather fluid mass, which appears to be 
identical with the content of the intestine. In the later 
stages the content of the caecum becomes gradually darker 
and more solid, acquiring at the same time the typical faecal 
odour. 
It may be well to point out that during early stages of 
faeces formation the rectum, i. e. the portion of the alimentary 
tract below the opening of the caeca, is always empty, and it 
is only in the later stages where the caecal content has already 
acquired the characteristic faecal appearance that anything is 
found in the rectum itself. 
We had hoped that it might be possible to associate certain 
stages in the parasites with stages in this conversion of the 
caecal content into the faeces. In this we have not been 
successful. On the other hand, there is a very distinct and 
characteristic change in the appearance of the bacterial flora 
during this process of faeces formation, to which we will 
return in a later part of the paper. 
