208 PROTISTS AND DISEASE 



besides the vaccine of Edward Jenner that is used in human 

 medicine. The first injection is an emulsion of infected 

 rabbit's spinal cord desiccated during 14 days ; and, in 

 increasing strength, doses of fixed virus are given for 15 days, 

 the last being of 3-day cord. 



Nucleoli. " The nature of true nucleoli is still imper- 

 fectly known " wrote Wilson in 1904. It may well be that 

 study oJ 



In reading the passage beginning " Specific remedies " it 



nucleus should be borne in mind that nearly everyone contracts measles 



of defer and scarlet fever, just as without vaccination we should all have 



, , small pox. If true vaccines were found I think they should 



be tried in measles and scarlet fever; but at the same time 



single m sterilising remedies should be sought for. 



f ragmem TO face P . 202 



appear t 

 one to g 



in Part v i isuggesteu tiiat tne specinc products oi the 

 highly specialised cells of metazoa, for example the secretions 

 of gland-cells, may be chromidial in origin. It seems as 

 though in nuclei that have permanent chromosomes there 

 may be a division of labour, reproduction devolving chiefly 

 on these whilst the nucleolus, in what we call resting nuclei, 

 furnishes secretions of different kinds for diverse purposes. 



Vaccines and pro-vaccines. As stated above there are 

 in human medicine only two vaccines, the Jennerian and the 

 Pasteurian. In general a vaccine is definable as an attenuated 

 culture of a pathogenic organism ; i.e. it contains living 



