334 PUBLIC HEALTH BACTERIOLOGY 



(Gilchrist) ; (6) An intraperitoneal tumour (Blanchard, 

 Schwartz, and Binot), etc. 



MOULDS. 



The distinguishing feature of the moulds is their growth 

 in long threads or filaments, with seed-bearing branches 

 called hyphae. Each filament may be a single, simple, 

 multinuclear cell, or a greatly branched one, or may be 

 composed of a row of cells set end to end. The interlacing 

 mass of threads is called the " mycelium." On this basis 

 moulds are divided into two classes : (i) Phycomycetes, 

 or those in which the mycelial threads consist of a single 

 cell ; and (2) Mycomycetes, in which the mycelial threads 

 are composed of numerous cells. The two groups also 

 differ in that in the first, reproduction is sexual and asexual ; 

 and in the second is by the asexual process only. All 

 moulds prefer an acid to an alkaline medium, and hence 

 are found attacking fruit preserves and similar substances. 

 The spores of moulds are present everywhere, and in 

 the air are in greater numbers than bacteria. 



The members of this group of fungi which we shall 

 consider are : Mucor mucedo ; Aspergillus ; Penicillium ; 

 Microsporon furfur ; M. minutissimum ; Sporotrichum 

 Beurmanni ; Oidium albicans ; and the moulds of ring- 

 worm. 



Mucor mucedo is the commonest mucor or " head " 

 mould, and belongs to the class of single-celled fungi or 

 phycomycetes. It is the common, white, cottony mould 

 which grows on camp bread, rotten fruit, horse dung, etc. 

 There is a finely branched mycelium from which project 

 thicker unbranched hyphae. Near the end of these hyphae 

 a septum forms, the terminal portion of the hypha swells, 

 and in it numerous oval spores develop. The globular 

 swelling produced is known as the " sporangium," and 

 is enclosed by a capsule. It ruptures when ripe by the 

 swelling of the gelatinous material in which the spores are 

 imbedded. The end of the hypha projects into the spor- 

 angium, and this part of it is called the " columella." This 

 asexual form of multiplication is the more common, but 

 sexual reproduction occurs under conditions not well defined. 



