CEECOMONAS. 241 



are always in motion, while Bodo (Fig. 118) is provided with a second 

 long flagellum, which is of a more rigid nature, and is generally 

 directed backwards. 



Each of these three genera contains forms which are said to occur in 

 man. So at least we learn from Steinberg's microscopic researches on 

 the white substances often found between human teeth. 1 For, besides 

 various Vibriones and the above-mentioned Amceba buccalis, he found no 

 fewer than nine different species belonging to the genera in question 

 Monas crepusculum, Ehrbg., M. globulus, Duj., M. lens, Duj., M. elongata, 

 Duj., Bodo socialis, Ehrbg., B. inteslinalis, Ehrbg., Cercomonas biflagellata, 

 Stbg., 0. acuminata, Duj., C. globulus, Duj. As I have had no oppor- 

 tunity of studying this memoir, which is but little known in Germany, 

 I can offer no opinion as to the extent to which these forms really differ, 

 nor as to the accuracy with which they are defined. But I think it 

 necessary to point out that the species mentioned by Steinberg have 

 hitherto, with few exceptions, only been observed living freely (Monas 

 globulus even in sea-water). Although this fact as to the known 

 mode of life of Monads by no means excludes a more or less frequent 

 parasitic occurrence, it appears to me in the meantime questionable, 

 especially considering the extreme difficulty of investigation and 

 determination, whether we are justified from these data alone in 

 reckoning the forms mentioned as human parasites. Yet Steinberg's 

 researches are sufficient to prove that the cavity of the human mouth, 

 with the putrefying organic remains and deposits between the teeth (in 

 caries also in the interior), may be a fertile breeding-place for Monads. 

 The same holds true, as we shall afterwards see, in regard to the genus 

 Trichomonas. 



Not less doubtful than the above forms are those Monads identified 

 by Wedl as Bodo saltans, Ehrbg. (O006 mm., Fig. 118), and Monas 

 crepusculum, Ehrbg. (0*004 mm.), which are described by him as 

 occurring often in great numbers upon unhealthy ulcers. 2 



Another Monad Bodo urinarius 3 which, according to the state- 

 ments of Hassall, occurs very often in cholera patients, but only in 

 albuminous alkaline urine, or along with Vibriones, can as yet hardly be 

 accurately determined. It is described as an oval or round granular 

 body of 0-0012 mm. in length and 0'0007 mm. in breadth, which moves 

 quickly by means of two (sometimes three, or only one) flagella, 

 and multiplies by division. Monads should only rarely be found in 

 normal human urine, since it is only the intermingled organic sub- 



1 Walter's Journal of Modern Medicine, Nos. 20-24, 1862 (Russian), Kief. 



2 " Grundziige der pathol. Histologie," p. 796. 



3 "General Board of Health," London, p. 293, 1855, and Lancet, Nov. 1859, 

 Schmidt's Jahrbiicher, Bd. cix., p. 157, 1861. 



Q 



