6 PROTOZOA AND DISEASE 



Contagious Epithelioma, or Molluscum Contagiosum. Recent ob- 

 servations on this disease may ultimately help to prove the true 

 character of the Cytoryctes Guarnieri. In birds the affection so closely 

 resembles that of the same name in man that the two affections 

 may be reasonably assumed to be of kindred character. In the 

 human subject during epidemics of small-pox the lesions are not 

 infrequently mistaken for those of the latter disease, and in birds the 

 term ' bird-pox ' is sometimes used for it. Now, the typical 

 molluscum corpuscle, which is in appearance an inert, homogeneous- 

 looking body, I know from personal observation, of which I have 

 some recent confirmation, to be a protozoon, which under suitable 

 conditions which as yet I have not fully determined, breaks up into 

 a swarm of flagellate bodies (see Fig. i). 



FIG. i. MOLLUSCUM CONTAGIOSUM. 



i, Molluscum body with oscillating particles ; 2, flagellate bodies derived 



from the same. 



Juliusberg 1 has found that the virus is filterable, but the incuba- 

 tion period is twice as long when filtered virus is inoculated as when 

 the material of the lesions is used directly. 



Burnet 2 found that inoculation of the cornea was followed by th 

 appearance in the corneal cells of bodies like the amoeboid stage of 

 Guarnieri's bodies in the vaccinated cornea. In conjunction with 

 my own observation, this discovery of Burnet's is of the utmost 

 significance, and goes far to support the view that Guarnieri's bodies 

 are not only specific for small-pox and vaccinia, but are themselves 

 one phase of a protozoon that causes the disease. 



1 Juliusberg, ' Ueb. das Epithelioma Contagiosum von Taube und Huhn, 

 Deutsch. Med. Woch., 1904, Nr. 43, p. 794. 



2 Et. Burnet, Annales de VInst. Pasteur, September 25, 1906. 



