HABITATS. 251 



sembled those of Sporidesmium polymorphum, under which name 

 specimens were at first published,* but this determination was 

 not satisfactory. The mycelium and erect threads are much too 

 highly developed for a good species of Sporidesmium, although 

 the name of Sporidesmium alternaria was afterwards adopted. 

 In fresh specimens of this fungus, when seen in situ by a half- 

 in'ch objective, the spores appear to be moniliform, but if so, all 

 attempts to see them so connected, when separated from the 

 matrix, failed. On one occasion, a very immature condition was 

 examined, containing simple beaded, hyaline bodies, attached 

 to each other by a short neck. The same appearance of 

 beaded spores, when seen in situ, was recognized by a myco- 

 logical friend, to whom specimens were submitted for con- 

 firmation.f 



. The last production which made its appearance on our wall- 

 paper burst through the varnish as little black spheres, like 

 grains of gunpowder. At first the varnish was elevated by 

 pressure from beneath, then the film was broken, and the little 

 blackish spheres appeared. These were, in the majority of cases, 

 gregarious, but occasionally a few of the spheres appeared 

 singly, or only two or three together. As the whole surface of 

 the damp paper was covered by these different fungi, it was 

 scarcely possible to regard any of them as isolated, or to declare 

 that one was not connected with the mycelium of the others. 

 The little spheres, when the paper was torn from the wall, were 

 also growing from the under surface, flattened considerably by 

 the pressure. The spherical bodies, or perithecia, were seated 

 on a plentiful hyaline mycelium. The walls of the perithecia, 

 rather more carbonaceous than membranaceous, are reticulated, 

 reminding one of the conceptacles of Erysiphe, to which the 

 perithecia bear considerable resemblance. The ostiolum is so 



* Cooke'a "Fungi Britannici Exsiccati," No. 329, under the name of 

 Sporidesmium potymorphwm var. charlarum. 



+ This reminds one of Preuss'a A Iternaria, figured in Sturm's ' ' Flora ; " it 

 has been suggested that the mould, as seen when examined under a power of 

 320 diam. , is very much like a Macrotporium. Again arises the question of the 

 strings of spores attached end to end. 



