6 Ward* — Recent Researches on the Parasitism of Fungi. 
by means of spores. We thus see that the period was ripening for 
great things, though little did the investigators of those days foresee 
what startling events were ahead of them. 
In 1870-6 Cohn (44) brought forward that splendid series of papers 
which will always establish his fame as the founder of bacteriology. Not 
only did he describe with marvellous accuracy, considering the technique 
of his day, a considerable number of Bacteria ; but he made observations 
on their movements, spore-formation, cell-contents and life-history, which 
put them at once on a definite footing as organisms to be classified and 
dealt with as were other plants, conclusions by no means so obvious then 
as now. Not only did Cohn establish the plant-nature of Bacteria, however, 
but he gave (45), in 1875, a scheme of classification of the various genera 
which has had to be reckoned with ever since, although the numbers of 
species or forms now known vastly outnumber the score or so known to 
Cohn in 1875 ; as may be seen by comparing Winter’s list (139) of sixty- 
nine species in 1884 with Migula’s estimate (111) of nearly 1,000 in 1896. 
Moreover, the definitions and characters of genera and species have under- 
gone great changes, as is readily seen on comparing the principal schemes 
of classification proposed by successive authorities, e. g. Winter (139), 1884, 
Van Tieghem (168), 1884, Zopf (209) in 1885, Fliigge (73), De Bary (19), 
and Hueppe (86) in 1886, De Toni and Trevisan (170) in 1889, Fischer (70) 
in 1897, and Migula (111) in 1896, each of whom has attempted to include 
the general results of the various and rapidly following discoveries con- 
cerning the general morphology, pigments, cilia, spore-formation and 
germination, mode of growth and division, and putrefactive, pathogenic, 
and other physiological properties of these organisms. 
In 1876 Cohn was enabled to introduce to a startled and incredulous 
world a practical result of the patient and faithful study of development 
introduced so successfully by De Bary, Pringsheim, and himself, which, 
taken together with De Bary’s proof of the infection of plants by the germ- 
tubes of parasitic Fungi in 1863, may be looked upon as the foundation of 
the parasitic or germ-theory of disease. This was Robert Koch’s paper on 
Die Aetiologie der Milzbrandkrankheit (99), in which he gave the principal 
phases of the life-history of Bacillus anthracis inside and outside the 
animal body, and thus started that important series of researches which, 
together with Pasteur’s work and the labours of numerous pupils, have 
brought such maladies as anthrax, tetanus, diphtheria, tubercle, and several 
other infectious or contagious diseases out of the region of mystery into the 
clear light of science. 
It is of course beyond the scope of this address to enter into the 
numerous collateral branches of successful research to which these results 
gave the initial impulse ; but I may remind you of the important position 
in any history of the science of the last thirty years which such subjects as 
