50 Tra n sac t ion a . — Miscellait iunis . 



each day for use in the inoculations at a specified time, and in 

 the condition of genuinely pure cultivations. There is no 

 stronger example of the power of the experimental method as 

 applied to medical matters than this one of the prevention of 

 a malady the absolute virus of ^hich is still obscure." Several 

 antirabic institutions have now been established throughout 

 Europe and America. The United Kingdom has none, although 

 about fifty British subjects have been treated annually in the 

 Paris Institute since 1886. The restrictions as to vivisection, 

 which in experiments on animals are painlessly conducted, 

 have not only rendered us dependent on Continental countries 

 for advances in biological and therapeutical science, but for 

 the care and treatment of such British subjects as may be 

 suffering from a highly dangerous malad> . It is within the 

 range of possibility that a parallel method of treatment may 

 be adopted for other infectious diseases in the human subject. 

 Should this come to pass it remains to be seen whether a false 

 sentimentality, which resists merciful experiments by which 

 thousands of lives of animals, as well as of human beings, may 

 be saved, while it allows pigeon-shooting and coursing to be 

 practised as sports , will continue to triumph over true humanity 

 and common-sense. 



Before considering the bacteria of sj^ecific diseases we will 

 inquire — (1) How it is possible for the body to resist an attack 

 of bacteria ; (2) How does spontaneous cure of fevers occur ? 

 (3) How does vaccination with attenuated virus prevent or 

 cure bacterial disease V 



(1.) In answer to the first question, we have now to 

 resume our acquaintance with the white blood-corpuscles, 

 which, as we saw-, play an important part in the j)rocess 

 of inflammation. What are these white corpuscles? In 

 1883 Dr. Elias Metschnikoff published some important ob- 

 servations on the intracellular digestion of invertebrates, 

 showing, from his own researches and from those of other 

 biologists, that the amoeboid cells of the mesoderm are cap- 

 able of ingesting and absorbing albuminoid particles. By 

 taking function as the standpoint for observation, instead 

 of merely considering form, he traced the white blood- 

 corpuscle of vertebrates to the same phylogenesis or com- 

 mon origin, as a class or race, as the amoeboid cells of the 

 mesoderm in the ^Nletazoa. It is necessary to call to mind 

 the signification of the terms "ectoderm," "endoderm," and 

 "mesoderm," which, of course, mean literally outer layer, 

 inner layer, and middle layer respectively. In the develop- 

 ment of the ovum the cells of the blastoderm or germ divide 

 into two layers, the ectoderm and the endoderm. In the 

 orders above Coelenterata a middle layer of cells appears, 

 probably derived from the other two. This is termed the 



