A. E. Shipley 
267 
Syngamus trachealis von Siebold, 1836. 
Another case of the continuity of the lining membrane of an organ 
being destroyed is that caused by the Syngamus trachealis found in the 
trachea of poultry and pheasants. This so-called red- or forked-worm 
pierces through the wall of the trachea and actually clenches the teeth 
with which its mouth is provided in the cartilaginous tracheal rings. 
So close is the attachment that the body of the worm will rupture if 
when once firmly fixed attempts are made to pull it away from the 
tracheal wall. If the trachea contains septic organisms and the 
cartilage were easily infected by them a more efficient inoculating 
medium could not be devised. 
Observations on other Vertebrates. 
Before passing on to consider the relation of the nematodes to the 
wall of the human intestine and caecum I should like to draw attention 
to one or two striking cases of lesions caused by thread-worms in other 
Vertebrates. 
The Horse. 
Such an instance is the Sclerostoma equinum so often found in the 
colon and caecum of the horse. This nematode pierces the mucosa 
until it reaches the capillary blood vessels and then engorges itself upon 
the horse’s blood. The walls of the alimentary canal infested with this 
parasite are dotted with small reddish ulcers which heal sooner or later 
according to the nature of the bacteria which have access to them. 
When the bacteria are pathogenic the ulcers are formed at the place 
of the lesion and here various forms of microbes are found 1 . These 
ulcerations can according to Weinberg extend until they attain an area 
of 23 mm. x 8 mm. In them the mucosa and often the sub-mucosa is 
destroyed and a marked infiltration of leucocytes, amongst which many 
bacteria occur, takes place in the deeper layers of the sub-mucosa. In 
other cases the ulcers are replaced by small abscesses some of which 
attain a considerable size (85 mm. x 33 mm.); they contain a fluid but 
there is little infiltration of leucocytes. These ulcers are especially 
common in horses that are wasting away and are attributed by 
1 Faure and Marotel (1902). I have not been able to see this Paper but I am 
indebted for a summary of it to Weinberg’s article (1907). From this I have taken 
many references and many statements. 
