22 
Mycologia 
Ascomycetes in which he demonstrated the pleomorphic condition 
of this class. His researches were based upon the comparison of 
many forms, their co-habitation, anatomy, and the alternation of 
their spore-forms. In this way he was able to work out the alter- 
nate asexual stages of a number of Ascomycetes. 
It may be mentioned that as a result of Tulasne’s work a storm 
of controversy developed which lasted for some time. On the 
one hand, pleomorphy was considered ridiculous by the most con- 
servative botanists of the time, while on the other hand his results 
led men of overenthusiasm to ridiculous conclusions. 
Owing to the importance of this group on account of its large 
number of species and their common association with plant dis- 
eases, it has occurred to the writer that any constant similarity 
existing between the conidial and ascigerous stages which might 
enable an investigator to conclude with some degree of certainty 
whether two stages are related would be of griat assistance. This 
information would be all the more valuable provided that it was 
of such a nature that it might be ascertained by a comparative 
study of the spores. 
While the author^ was working upon the correlation existing 
between certain species of rusts his attention was first called to 
the similarity between conidia and ascospores of certain species of 
Ascomycetes, the genetic connection of which has been demon- 
strated. This paper is the result of observations and notes taken 
from time to time upon such species as may be said to show struc- 
tural parallelism between their conidia and ascospores. 
A similar parallelism between certain spore-forms in the Ure- 
dinales has been pointed out by Arthur^, who worked out the con- 
nection existing between Aecidium verbenicola and Puccinia Vil- 
fae,^ Aecidium Traxini and Puccinia peridermiospora* and 
Aecidium Cephalanthi and Puccinia Seymouriana.^ He compared 
the peculiar morphology of the aeciospores with the same peculi- 
2 Orton, C. R., Correlation between certain species of Puccinia and Uro- 
myces. Mycologia 4; 194-204. 1912. 
3 Arthur, J. C., Cultures of Urcdineae in 1899. Bot. Gaz. 29: 268-276. 
1900. 
4 Arthur, J. C., The Urcdineae occurring upon Phragmites, Spartina, and 
Arundinaria in America. Bot. Gaz. 34; 1-20. 1902. 
5 Arthur, J. C., loc. cit. 
