M. C. COOKE ON BLACK MOULDS. 251 



species of Helminthosporium, or even to those found in Britain. 

 This genus is the great glory and pride of those Mycologists who 

 devote themselves to the Black Moulds, and, if it were only for 

 their encouragement, I could have wished to have lingered over it 

 more than I can permit myself to do. There are several good 

 types of spore-form to be found in this genus, which might be indi- 

 cated as suggestive of a grouping for the purposes of study. For 

 instance, there is the fusiform type, illustrated by H. fusiforme, H. 

 apiculatum, H. velutinum, H. gongotrichnm, and others. There is 

 also the follieulate type, as exhibited by II. folliculatum, H. scole- 

 coides, and H. rhopaloides. There is also the type of spore very 

 much elongated, whilst the thread is reduced to a minimum, as in 

 H. Tilioe and H. Smithii, and the pyriform type, as in H. turbin- 

 atum, H. altum, H. obovatum, &c. I might also enumerate the 

 clavate type, as in H. macrocarpum, H. appendicu latum, &c, and 

 the triseptate type, as H. Rousselianum, H. subulatum, and several 

 foreign species. 



This grouping, which is merely suggestive, and not the result of 

 any matured consideration, will serve to show the great variety 

 which exists in the form of the spore in this large genus, and it is 

 this feature which perhaps would alone recommend them to micro- 

 scopists outside the special circle of Fungologists. No finer spores 

 can be found than those of Helminthosporium Smithii* which occurs 

 on twigs of holly, lying on the ground under hollybushes. A 

 different kind, but still very interesting clavate or follieulate spores, 

 occur on H. folliculatum, which is not at all uncommon on old 

 cabbage stalks, cast aside to rot in the rubbish corner of a kitchen 

 garden ; whilst //. macrocarpum, with its large coarse opaque 

 threads, and club-shaped spores, will undoubtedly be found on chips 

 and sticks lying on the ground, with perhaps one or other of the 

 fusiform spored species. 



Many years ago, when Schweinitz was in North America, he 

 found a black mould on the leaves of Carices, which had some re- 

 semblance to Hvlminthosporium, but, instead of the prominent, erect 

 threads which are common to that genus, it had creeping flocci, and 

 long erect spores. To this fungus he gave the generic name of 

 Clasterisporium. It was for a long time doubted in Europe whether 

 Schweinitz was justified in constituting a single aberrant form into 

 a new genus, and hence Clasterisporium came to be scarcely recog- 

 * " Quekett Journal," No. 11, plate 7. 



