Ward. — Recent Researches on the Parasitism of Fungi . 3 
Indeed Cohn’s papers on Pilobolus (42), 1852, Chytridium (43), 1855-6, 
Empusa (48), 1855, an d Uber Pilze als Tierkrankheiten (47), in 1854; 
Pringsheim’s on Aehlya (137), in 1857 ; and De Bary’s on Achlya( 13), 1852, 
Aspergillus (14), 1854, and Myxomycetes (11), 1858, in the recently founded 
Botanische Zeitung, and above all, his Untersuchungen u. d. Brandpilze (4), 
1853, laid a foundation for an edifice of philosophical science which has 
been building ever since, and becoming statelier and statelier as it grows. 
Darwin’s Origin of Species (54), which appeared in 1859, of course 
deals in no way especially with Fungi, but we must note that it gave impetus 
in a marked degree to such work as I have just referred to, because in no 
branch of investigation had the problems of evolution and of species come 
more prominently into the foreground ; and the fullest acceptance of the 
developmental method and of the theory of evolution was already evident 
in De Bary’s Morphologie und Physiologie, & c. (10), which came out in 
1866, i. e. seven years after the Origin of Species. 
In this classical work De Bary not only brought together the results 
of his discoveries on the germination of spores and the proofs of direct 
infection by means of germ tubes in Peronosporeae, Uredineae, &c. (first given 
(5) in the Ann. des Sc. Nat., 1863), but he also generalized on the real 
significance of parasites on and in plants and insects, &c., and rendered 
clear the distinction between saprophytes and parasites. 
De Bary also brought together the then recently discovered facts 
concerning sexual reproduction in the Fungi ; and although some of his 
conclusions have not withstood the test of time, no investigator can afford 
to overlook the importance of his ideas. 
Of equal, or even greater, importance to the development of the subject 
was his chapter on so-called pleomorphy and alternation of generations in 
Fungi. Tulasne had (176), in 1851, called attention to the fact (anticipated 
to some extent by Corda (51)) that one and the same species of Fungus may 
produce a succession of two or more totally different kinds of spores and 
of spore-bearing apparatus ; and had thus wiped out at one blow, as it were, 
a number of genera of Fungi which were nothing more than descriptions of 
a Fungus in one particular stage of its development, which same Fungus in 
another stage (when bearing one of its other kinds of spore) had hitherto been 
described as belonging to some other genus. But Tulasne’s proofs, as was 
usual with him, depended chiefly on observation of the contiguity of forms. 
De Bary, however, proved by direct sowing of the Fungus, and observation 
of its development, that a particular spore produced a mycelium which then 
bore the second form of spore; and thus showed how to criticize the 
numerous reckless statements of careless observers which were rampant then 
and soon afterwards. 
But the most striking of all De Bary’s numerous striking discoveries 
was his proof of heteroecism in Puccinia graminis , first recorded in his paper 
