226 THE PROTOZOA 



and ascitic fluid are ground in a mortar, heated to 60 C. for one hour then, with the 

 final addition of i% trikresol, we have an emulsion called "luetin." This extract 

 produces an allergic reaction on the skin of certain syphilitics (Luetin reaction). 

 To carry out the test luetin is introduced intradermally at the insertion of the left 

 deltoid and a control emulsion of agar media injected in the right arm. A negative 

 result shows as an erythema without pain or papule formation. Positive reactions 

 show as papules vesicles or even pustules giving rise to discomfort for several days. 

 While the control side usually becomes normal in forty-eight hours yet in latent 

 and tertiary syphilis the control may show almost as marked a reaction. The term 

 " Umstimmung " is applied to this susceptibility to trauma of the skin of those having 

 tertiary syphilis. Some cases of parasyphilitic infections which are negative to the 

 Wassermann test give a positive luetin reaction. 



Noguchi has recently demonstrated T. pallidum in all layers of the cerebral 

 cortex except the outermost one in 12 cases out of 70 cases of general paresis examined. 



In diagnosis either use the dark ground illuminator or make a thin smear from 

 the sanious oozing after vigorous friction of the chancre with gauze, taking up this 

 blood-stained serum on the end of a slide and smearing the surface of a second slide 

 with the adhering material. It is in most cases more satisfactory to curet the lesion, 

 in this way obtaining material from the areas of the thickened arteries. 



In the diagnosis of cerebrospinal syphilis we use, in addition to the Wassermann 

 test of the blood, (i) the Nonne-Apelt reaction in which about i c.c. of a saturated 

 aqueous solution of ammon. sulphate is added to an equal amount of cerebrospinal 

 fluid. If turbidity or rather opalescence appear immediately, or within three minutes, 

 the test is positive. (2) The counting of the lymphocytes in the cerebrospinal 

 fluid. A lymphocytosis occurs in cerebrospinal syphilis, tabes and general paresis. 

 (3) The Wassermann test, using the cerebrospinal fluid instead of blood-serum. 



T. pertenue. An organism of similar morphology was first reported 

 by Castellani as present in yaws. It is found in smears and sections as 

 with T. pallidum. 



A point of distinction between these spirochaetes is that the T. pallidum is found 

 in abundance in sections from a chancre about the thickened arteries in the corium, 

 while in sections from a yaws nodule the T. pertenue is found chiefly in the region 

 of the interpapillary pegs of the Malpighian layer of the epidermis where they bound 

 the papillary layer of the corium. 



T. pertenue has been cultivated in the same way as T. pallidum and Nichols has 

 infected rabbits by intratesticular injection. A disease of Guam known as gangosa 

 is possibly connected with a tertiary form of yaws. In persons who have had yaws 

 a positive Wassermann reaction seems to be given in a higher percentage than is 

 true for syphilis. Salvarsan is also more specific for yaws than for syphilis. 



Trypanosoma. 



The genus Trypanosoma has a more or less spindle-shaped body, 

 along one border of which runs an undulating membrane. There is one 

 flagellum bordering the membrane and projecting like a whip posteriorly. 



