142 ERIKSSON, MARSHALL WARD's RESEARCHES ON BROWN RUST. 



expression to this my opinion iu the following manner. »1 

 do not deny the possibility of a day coming when micro- 

 technical science shall have attained to a higher degree of 

 perfection, and when we shall have the help of micro-chemi- 

 cal methods which will be better than those we now have 

 at our disposal. It will then, perhaps, be possible to reduce 

 what I have termed Mycoplasm into two organisms, differ- 

 ing from a morphological point of view. Until such a mo- 

 ment arrive let us admit of the use of the term here em- 

 ployed».^ 



Marshall Ward is neither the first nor the only person 

 who has omitted to make a clear distinction between the two 

 essential moments of my theory, recapitulated above. In a 

 word, nearly every writer who has expressed himself on the 

 question has, when unable for some reason or other to agree 

 with the proposed solution, also rejected the first moment 

 of the theory, viz. the existence of an internal germ of dis- 

 ease, and this has been done without any reason at all being 

 given. 



Now Marshall Ward accentuates in his last communi- 

 cation to the Royal Society that he has been busy for a 

 year and a half with a comprehensive histological research, 

 based on the application of improved hardening and staining 

 methods, and that this research has persuaded him that 1 

 have erroneously interpreted certain microscopic preparations 

 upon which my opinions were based. But these histological 

 researches of Marshall Ward have, however, been carried 

 out with leaves which had been infected with uredo- 

 spores. After 1, 2, (> and 8 days, preparations have been 

 made of the infected leaf-flecks and, parallel with these, pre- 

 parations of non-infected leaves have also been made. The 

 strict examinations afterwards carried out showed that I had 

 »entirely reversed the true order of events» and that the 

 mycoplasm hypothesis, i. e. the whole theory of an internal 

 germ of disease, was »untenable». 



1 cannot but deeply deplore that Marshall Ward should 

 have drawn such erroneous conclusions from a research so 

 valuable in itself as 1 premise this to be, and as this cannot 

 be otherwise explained than by the fact that Marshall Ward 



* J. Eriksson, Sur Vorigine etc., T. 15, p. 69. [Extr. p. 193]. 



