208 FUNGI. 



known as Spharia (Pleospora) herbarium. First of all the very 

 common mould called Cladosporium herbarum is constituted as 

 conidia, and of this again Macrosporium sarcinula, Berk., is con- 

 sidered to be another condition. In the next place, Cytispora 

 orbicularis, Berk., and PJwma herbarium, West, are regarded as 

 pycnidia, enclosing stylospores. Then Alternaria tenuis, Pr.,* 

 which is said to be parasitic on Cladosporium hcrlarum, is held 

 to be only a form of that species, so that here we have (including 

 the perithecia) no less than six forms or phases for the same 

 fungus. As Macrosporium Cheiranthi, Pr., often is found in 

 company with Cladosporium herbarum, that is also open to 

 suspicion. 



We have adduced in the foregoing pages a few instances 

 which will serve to illustrate the polymorphism of fungi. 

 Some of these it will be observed are accepted as beyond doubt, 

 occurring as they do in intimate relationship with each other. 

 Others are considered as scarcely so well established, but 

 probable, although developed sometimes on different species of 

 plants. Finally, some are regarded as hitherto not satisfactorily 

 proved, or, it may be, only suspicious. In this latter group, 

 however much probability may be in their favour, it can hardly 

 be deemed philosophical to accept them on such slender evidence 

 as in some cases alone is afforded. It would not have been 

 difficult to have extended the latter group considerably by the 

 addition of instances enumerated by various mycologists in 

 their works without any explanation of the data upon which 

 their conclusions have been founded. In fact, altogether this 

 chapter mast be accepted as illustrative and suggestive^ but by 

 no means as exhaustive. 



* Corda, " Prachtflora," plate vii. 



