PLASSOMYXINEAE 121 



disease of pigeons calls for re-investigation. Burnet quotes 

 Carnwath as having found the virus of bird-pox to be the 

 same as that of flagellate-diphtheria. 



Pfeiffer described the healing of lesions in pigeons to 

 be like that of human vaccine vesicles. 



The molluscum body in birds has been described as 

 " melting away " when placed in water. I have seen nothing 

 like that in human molluscum ; but it is quite possible that 

 in birds the bodies grow more rapidly, are softer, more 

 labile, and in water break up quickly into microhenads. 



Inoculation of a bird, M. Borrel observes, is easy : all 

 that is required is to rub a little virus on a feathered part 

 and multiple tumours follow just as vaccine is followed by 

 vesicles if rubbed on the shaven skin. 



Bird-molluscum must be one of the easiest of all diseases 

 to investigate. All the necessary material can be obtained 

 in the course of treating an ailing pigeon medically, with as 

 much consideration as though it were a human being. No 

 pain need be caused. No license to experiment on living 

 animals is required for most of the work. 



Further Details of Culture-Method. In giving these 

 simple instructions I have a hope that others who have 

 access to material may be led to repeat and extend, or to 

 correct my observations, which have been too often inter- 

 rupted by other affairs. 



The necessary apparatus need not occupy more than a 

 square foot of space in a consulting-room and cannot but 



