310 SUMMARY OF CURRENT RESEARCHES RELATING TO 



inclines to believe that it has. Both conjugation and endomixis secure 

 Te-arrangement of the molecular constitution of the cell — conjugation by 

 amphimixis, endomixis by internal re-organization. Both may be reju- 

 venating and be followed by an acceleration of vital processes. ' 



Flagellate Infections of Intestines and Liver.* — P. B. Hadley 

 publishes an account of an experimental study of the role of the 

 flagellate Protozoa in infective processes of the intestines and liver. 

 The Trichomonas studied is a flagellate Protozoon found in the intestines 

 of all poultry, as well as of other animals. It is pear-shaped, elongate, 

 half-moon-shaped or globular according to the stage of development. 

 It manifests the usual Trichomonas characteristics. The flagellates are 

 present in the ccecal contents, but are found mainly in the mucous layer 

 overlying the epithelium and often deep in the crypts of Lieberkiihn, 

 The morphology, encystation, and conjugation of the parasite are 

 described, and the pathological coecal symptoms, macroscopical and 

 microscopical, are indicated. The author concludes that intestinal 

 flagellatosis cannot be regarded as an infectious disease, and Trichomonas 

 as found in these cases (" blackhead " in turkeys) is not a pure, but 

 only a facultative parasite. A successful infection depends upon factors 

 present in the host, and is probably quite unrelated to virulence on the 

 part of the infecting organism. 



A second paper f by the same author describes the avenue and 

 •development of tissue-infection in intestinal trichomoniasis, and gives 

 evidence of the identity of certain stages in the development of 

 Trichomonas with Amijcha mehagridis, first reported by Theobald Smith, 

 and maintained by him to be the cause of the disease. The writer 

 "Concludes that the presence of large numbers of flagellates in the coecal 

 canal is not the cause but the result of the accompanying and preceding 

 diarrhoea. 



Structure and Division of Nyctotherus ovalis.f — Antonio de 

 2uluetta has studied this Heterotrichous commensal in the intestine of 

 the cockroach {Blatta orientalis). The endoplasm is divided by a 

 diaphragm which is in contact centrally with the anterior surface of the 

 nucleus and is united peripherally with the cortical layer. The endoplasm 

 of the anterior region has a more distinct, alveolar structure than 

 the posterior region, and is also more limpid. During division the 

 diaphragm disappears, the endoplasm becomes uniform. When the 

 daughter-individuals have attained a certain size the endoplasm 

 re-differentiates in each into two regions, and a new diaphragm is 

 formed. The diaphragm appears as a lamella of variable thickness, 

 striated or sub-fibrous radially. It is probably comparable to the 

 partition between the protomerite and deutomerite in Polycystid Gre- 

 garinids. The figures given are very interesting. 



• Agric. Exper. Stat. Rhode Island College, Bull. 166 (1916) pp. 1-40 (3 pis.). 



t Agric. Exper. Stat. Rhode Island College, Bull. 168 (1916) pp. 1-64 (11 pis. 

 and 2 iigs.) 



t Trabajos Mus. Nacional Ciencias Naturales, Madrid, serie Zoologica, No. 26 

 (1916) pp. 1-16 (6 figs.). 



