WATANABE: ON THK SO-CALLKD BLACK HEAD OF TUKKEY. 73 



Slitters iujurv ; this is esj^cially the casf \n tin- walls of tlu' Lielx'rkühn's crvpts : 

 the ervpt's walls are destroyed at several parts which the parasites attack iu 

 ninltitude t(^ make their way into the interior of the crypt's lumen, as stated iu 

 the foreooiuir lines. I call attention to this point of destruction by the parasites : 

 nam* ly, the parts of the crypt's walls, which are destroyed in consequence of the 

 parasitism, form the only way of escape of the parasites. The animals come to the 

 interior of the aiecura through the crypt's walls broken up and are ea.st oif to the 

 exterior, being intermingled A\"ith the ccecal contents, n^z. the fieces ; in this way they 

 mav infect other host individuals. 



B. The Coecal Contents. 



Having dealt with the diseased features of the cceca, the crecal contents will 

 briefly be examined, in order to make intelligible the relations of the parasitic 

 organisms which may be found in the contents, to the diseased part^ of the cceca. 



The contents of the turkey's cteea are hard, owing doubtless to the action of 

 the preserving reagent employed. They are coagulated, though semifluidal in 

 tlieir fresh state, being greenish in colour similar to those taken off from the fc»wl's 

 coeca. A microscopical examination shows that the c<ecal contents consist mainly 

 of undigested parts of their f(X)ds, such as the vessels and fibers of plants. Only 

 <»ne sp'.'cies of animal parasite is detected, but numerous in individual number. It 

 is a species of the genus Trichostomwn of Triehocepahda?, Xenuitoda. Bacteria are 

 found in abundance : at least six species are to be distinguished. All these 

 vegetative parasites have, it seems, certain physiological meanings in causing putrefac- 

 tion to the food undigested. There are fi;»uud many epithelial cells whicli .show 

 a great similarity with those forming the mucosa layer : they have doubtless fallen 

 off from this layer iu consequence of artifact. It is very striking that there are 

 detected only a few individuals of the parasitic protozoöu which was n cognised, 

 in the foregoing lines, as causing the disease. There is, therefore, little room for 

 dotibting that these parasitic cells are on their way escaping from the avail walls 

 where they live in colony. 



C. The Liver. 



The liver of a diseased turkey shows resemblance to the fowl's liver in its 

 external configuration. On the surflice of the liver, we find numerous coloured 

 .spots varying in size. They are in some cases 17 mm in diameter, while in (ither 



