INFUSORIA 507 



may be carried out by putting up a series of tubes containing either 

 diminishing quantities of the serum or diminishing quantities of 

 antigen, the other constituents remaining the same in either case. 



As human serum generally contains amboceptor hsemolytic for 

 sheeps' corpuscles, Flemming * devised a method in which the 

 test serum itself with sheep's corpuscles constitutes the haemolytic 

 system, and the test is also carried out with Wright's pipettes. 

 Emery 2 in his method makes use of human corpuscles and of the 

 complement present in the test serum so that addition of com- 

 plement is unnecessary (in this case, of course, the test -serum is 

 not inactivated). 



The examination of a very large number of cases of syphilis by 

 different observers indicates that the test is of very considerable 

 value and diagnostic significance. In conditions such as tabes 

 dorsalis and general paralysis of the insane, which on other grounds 

 are generally regarded as due to syphilis, 52 per cent, give the 

 reaction. A positive reaction may be said to show a positive, and 

 probably active, syphilitic infection, but a negative reaction does 

 not necessarily exclude syphilis. Energetic mercurial treatment 

 may render the reaction negative. 



(4) Forges' reaction. If syphilitic serum be added to a solution 

 of lecithin or other lipoid substances, in many cases it gives a white 

 precipitate. Normal or non-syphilitic serum gives no precipitate. 

 This has been tried extensively as a substitute for the Wassermann 

 reaction, but it is not so delicate. 



Class III. Infusoria (Ciliata) 



The Infusoria are protozoa the locomotive organs of which 

 consist of cilia, and in which the nuclear apparatus is differentiated 

 into a vegetative macronucleus and a generative micronucleus. 

 The cytoplasm is enclosed within a cuticle, an oral aperture is 

 present in the form of a slit or pore, and waste matter is extruded 

 by a pore, constant in position, but, as a rule, visible only when in 

 use. A contractile vacuole is generally present. Reproduction 

 usually takes place by fission, which is preceded by division of the 

 two nuclei, the micronucleus by mitosis, the macronucleus by direct 

 division. 



The Infusoria are not of much pathological importance, but are 

 common in ponds and ditches, e.g. Paramecium and Vorticella. 



1 Lancet, 1909, vol. i, p. 1512. 



2 Ibid. 1910, vol. ii, September 3. 



