HABITATS. 249 



denizens of the wall to the microscope, and this curiosity was 

 increased week by week, on finding that none of the forms 

 found vegetating on nearly two square yards of damp wall 

 could be recognized as agreeing specifically with any described 

 moulds with which we were acquainted. Here was a problem 

 to be solved under the most favourable conditions, a forest of 

 mould indoors, within a few yards of the fireside, growing quite 

 naturally, and all strangers. Whence could these new forms 

 proceed ? 



The cottony tufts of white mould, which were the first to 

 appear, had an abundant mycelium, but the erect threads which 

 sprang from this were for a long time sterile, and closely inter- 

 laced. At length fertile threads were developed in tufts, mixed 

 with the sterile threads. These fruit-bearers were shorter and 

 stouter, more sparingly branched, but beset throughout nearly 

 their whole length with short patent, alternate branchlets. 

 These latter were broadest towards the apex, so as to be almost 

 clavate, and the extremity was beset with two or three short 

 spicnles. Each spicule was normally surmounted by an obovate 

 spore. The presence of fertile threads imparted the ochraceous 

 tint above alluded to. This tint was slight, and perhaps would 

 not have been noticed, bat from the close proximity of the snow- 

 white tufts of barren threads. The fertile fiocci were decumbent, 

 probably from the weight of the spores, and the tufts were a 

 little- elevated above the surface of the matrix. This mould 

 belonged clearly to the Mucedines, but it hardly accorded well 

 with any known genus, although most intimately related 

 to JthinotrickwH, in which it was placed as Rhinotrichum 

 lanosum.* 



The white mould having become established for a week or 

 two, small blackish spots made their appearance on the paper, 

 sometimes amongst thin patches of the mould, and sometimes 

 outside them. These spots, at first cloudy and indefinite, varied 

 in size, but were usually less than a quarter of an inch in 

 diameter. The varnish of the paper was afterwards pushed off 



* Specimens of this mould were distributed in Ccoke's "Fungi Britannic? 

 Exsiccati," No. 356, under the name of Clinotrichum latioxwn. 

 12 



