142 M. C COOKE ON SOME REMARKABLE MOULDS. 



matters prevented my pursuing the cultivation any further, and I 

 never attempted to learn what was the ultimate destination of the 

 sclerotia. 



There are some points in which the capituli of this mould differ 

 in their composition from those usual in Polyactis, but this is 

 merely a systematic question which the systematizers must settle 

 for themselves. The parasite is undoubtedly an injurious one, 

 extending speedily to every leaf on young trees, and as such is 

 worthy of its name. 



Polyactis truncata, Cooke, in Bommers " Champignons de 



Bruxelles^ p. 137. 



Advantage may be taken of this opportunity to give details of a 

 white mould on the fronds of ferns, which was communicated to 

 me from Belgium by Madame Bommer. Although placed in the 

 same genus, it differs in many particulars from the one to which I 

 have just alluded. The tufts were small, and consisted of but a few 

 fertile threads. The hyphae slender, flexuous and septate, sur- 

 mounted by a rather irregular subglobose head. When the spores 

 were removed the upper portion of the thread which formed the 

 capitulum was found to be repeatedly branched, in a somewhat 

 furcate manner, each branch being very short ; the ultimate ramuli 

 being fastigiate, or digitate. Each minute branchlet bore at its 

 extremity an elongated elliptical, but abruptly truncate spore ('02 

 mm. long x *007 mm. broad). When the spores became free each 

 end was truncate. When the specimens were examined I was 

 under the impression that the truncate, sometimes concave, ends 

 of the spores might be caused by the falling in, or collapse, of the 

 thinner extremities of the epispore, but of this 1 could not be 

 assured. 



Although there is a determination in some quarters to suppress 

 the genus Polyactis altogether, for the sake of a change, I have 

 still retained these names. It is one of my many failings, which 

 some friends seldom fail in reminding me of, that I am persistently 

 heterodox, inasmuch as I will not shift and veer in all directions, 

 as the weathercock has done with us every day during this bluster- 

 ing month of March. Such mycological veering of the mycolo- 

 gical weathercock being determined by the explosion of some wind- 

 bag in some corner of Continental Europe. These incidental words 

 lead me still further to protest that alterations in genera, whether 



