58 
C. H. MARTIN AND MURIEL ROBERTSON. 
typical active forms of these flagellates are shown in the 
following table, and the nomenclature that we have adopted 
for the various parts can be seen in the text-figures. 
The literature upon rectal protozoan parasites has in recent 
years attained such dimensions that it is impossible to give 
here a detailed historical account of the work done by other 
observers. Under these circumstances, we have decided to 
content ourselves with discussing in our final summary the 
more obvious differences between our results and those of 
earlier workers on other forms. On the other hand, the 
literature dealing specifically with the protozoan fauna of the 
alimentary tract of the fowl is very limited, and as we 
have already discussed it fairly fully in our preliminary 
account of these forms, we need here only refer to one or 
two essential points. 
Eberth, in 1862, first described these flagellate parasites 
from the caecum of the fowl as “Ein kleines Infusorium, 
though he did not give them any name. 
Stein, in 1878, first put forward the view that these para- 
sites were Tricliomonads in which the anterior flagella had 
been overlooked, and Leuckart, in the second edition of his 
book, ‘ Die Parasiten des Menschen/ arrived at the same 
conclusion. (In his first edition he placed these forms in a 
new genus — Saenolophus.) 
This view of the Trichomonad affinities of these forms 
was later disregarded by Saville Kent in his monograph of 
the Infusoria (1881), where the name of Trypanosoma 
eberthi Avas given to these flagellates, and in this vieAV he 
was followed by Biitschli (1889). Most of the later Avorkers 
on parasitic flagellates — Doflein, Laveran, Mesnil — have 
regarded these parasites as Trichomonads, but haA^e not fur- 
nished any evidence in faA r our of this view. Liihe, in a short 
note in Mense’s * Handbuch der Tropenkrankheiten/ has 
changed the name from Trypanosoma Eberthi to Spiro- 
chaeta Eberthi, probably on account of Eberth’s original 
figures, in which the only part of the animal that is clearly 
shoAvn is an undulating membrane. It is evident, Ave think, 
