xin, b, 5 Haughwout: Flagellated and Ciliated Protozoa 233 



Apparently the parasites gain entrance to the tissues through 

 the goblet cells of the crypts of Lieberkuhn. They accumulate 

 in large numbers in the fundi of the crypts, causing the walls 

 to bulge, with the result that the parasites are literally forced in- 

 to the goblet cells, past the nucleus and cell wall, until finally they 

 enter beneath the epithelium of the crypt. The passage once 

 made, other trichomonads follow and collect in a mass between 

 the epithelium and the basement membrane. 



This tendency to collect about the surface of the epithelium 

 has been noted by other workers. Kofoid and Swezy(26) and 

 Martin and Robertson (29) mention it in connection with their 

 search for dividing forms. 



Next the parasites push through the basement membrane into 

 the connective tissue of the mucosa and thence to the mwscularis 

 mucosa? and submucosa. The invasion is described as being of 

 an intracellular nature as in the case of the Sporozoa. 



Smith (46) has discussed at length some peculiar bodies he 

 found in 1916 in a turkey suffering supposedly from blackhead, 

 which he was inclined at the time to regard as coccidia that 

 had wandered beyond their accustomed habitat, the epithelium. 

 Characteristic lesions of blackhead were absent, and several coc- 

 cidial cysts were found in the faeces. The article is too long to 

 quote in extenso, but the author mentions certain things that 

 may have a bearing on Hadley's observations. Sections of the 

 intestinal tract showed that the epithelium had been lifted from 

 the core of the villus, leaving the space intervening filled with 

 a precipitate of fine granules. The parasites appeared as an 

 almost continuous band near the margin of the villus core. The 

 striking feature seems to be the appearance of these bodies, 

 which were vacuolelike and partially empty. A few were filled. 

 Smith says : 



They consisted of some host cell whose cytoplasm had been moulded into 

 a shell (or ring in section) with the much flattened nucleus against this 

 shell. The contents were a very fine lining membrane within which were 

 roundish bodies of various diameters 2 m and more, staining feebly reddish 

 and with or without a mass of chromatin. Frequently a body contained 

 two chromatin masses situated at opposite poles, as if division had taken 

 place. Those bodies which were full of spheres, contained about sixteen 

 or more of more or less uniform size. The vacuolated appearance under 

 low power was due to the disappearance of some or all of the parasitic 

 contents of the host cell. Prolonged search for the characteristic products 

 of asexual multiplication — falciform bodies — brought to light only two or 

 three parasites containing them. It is not to be denied that these may 

 have been moulded into crescent shape by the pressure of the other growing 

 and segmenting members in the same membrane. 



156022—2 



