194 PROCEEDINGS OF SOCIETIES. 



worms, and many forms of useful vegetable life. These moulds, 

 however, belong to special species, and are not commonly met with, 

 and it is my purpose to confine myself to those met with continually in 

 every-day life, and which infest our bread, cheese, preserves, pickles, 

 ink, beer, fruits, and decaying vegetables ; also our boots, our linen, 

 our cotton goods en route for India or China, and even our very teeth 

 and the mucous membrane of our throats. These belong, for the most 

 part, to the genera Aspergillus, Penicillium, and Mucor, the two former 

 being hyphomycetous, and the latter physomycetous. 



The mould which has most frequently come under my notice is 

 Aspergillus glaucus, the presence of which in its favourite nidus, cheese, 

 is considered by some of my friends (and I must plead guilty myself 

 to the soft impeachment) to greatly improve its flavour. I have found 

 it on Manilla cigars, on preserves, on Radix althce, or the marsh- 

 mallow roots of the shops, on horn, old oak, mistletoe, old shoes, and, 

 in fact, everywhere. The name aspergillus has been given in conse- 

 quence of some resemblance to the aspergillus or mop-like brush used 

 in Eoman Catholic countries to sprinkle the holy water with. In its 

 young state it presents nothing to our view but a rapidly-spreading 

 white articulated mycelium., which, however, soon, under favourable 

 circumstances, throws up erect fertile threads, bearing on their 

 apices globular heads, from which chains of spores radiate, and thus 

 give a mop-like appearance to the ripe fruit. In course of time these 

 chains of spores fall off, and leave the globose head, which may then 

 be observed covered with short spiny processes, probably the points 

 of attachment of the chains of spores. These spores are globular 

 in form, and seem to me to be irregular in size — 3, 2 7, or even 2, 

 sometimes filling the micrometer space for 1-1000 in. They present 

 a most beautiful appearance under the binocular with a ^-inch power. 

 Aspergillus has been found in the lungs and air-sacs of birds, also in 

 the external conduit of the ear. 



The next form of common mould is Penicillium, which also belongs 

 to the hyphomycetous family, and natural order Mucedines. The most 

 common is Penicillium ylaucum, which is found in great abundance, in 

 the form of bluish and greenish mould, on decaying vegetable sub- 

 stances generally, but especially on semi-fluid or liquid matters, form- 

 ing a dense pasty crust, slimy on the lower surface, and bearing spores 

 on the upper, Its general appearance is similar to that of Aspergillus 

 glaucus, and it is only by the aid of the microscope that, we can distin- 

 guish them. Its mycelium consists of interwoven articulated filaments, 

 extensively ramified, and bearing fertile threads, also articulated, upon 

 the apices of which are developed septaB or branchlets, consisting of 

 an elongated cell, or cells, sometimes simple, sometimes forked, but 

 each bearing a chain of spores, frequently arranged in a peniciliate or 

 brush-like form ; hence its name. The spores are of various colours, 

 according to age and circumstances, but green of some shade generally 

 prevails. They are elliptic in form, and thus easily distinguishable 

 from those of Aspergillus. They are also smaller, and more even in 

 size ; at least, such is my experience of them, about six placed side by 

 side filling the micrometer space for 1-1000 in. The specimens on 



