MOULDS 569 



grow, and its protoplasm undergoes multiple fission into numerous 

 ovoid masses, the spores, each of which becomes surrounded with a 

 cellulose capsule. The septum separating the sporangium from 

 the hypha projects upwards into the interior of the sporangium 

 as a club-shaped knob known as the columella. When the 

 sporangium is ripe the slightest touch causes its wall to rupture, 

 so liberating the spores. 'When placed under favourable condi- 

 tions the spore germinates, and the buds increase in length and 

 ultimately form hyphaB. 



Occasionally a process of conjugation occurs. Two adjacent 

 hyphse send out lateral branches which come in contact with one 

 another, and a septum forms in each, separating a small portion of 

 protoplasm from the rest of the hypha. The apposed walls of the 

 two cells become absorbed and the contents mingle. The mass of 

 protoplasm so formed becomes surrounded with a thick cell-wall, 

 giving rise to an inactive spore-like body, the zygospore, which 

 under favourable conditions develops like an ordinary spore. 

 Some Mucors form thick-walled resting cells, known as chlamydo- 

 spores, in the vegetative mycelium. These are storehouses of 

 reserve material which is ultimately expended in the production 

 of shoots. 



Certain Mucors form appreciable amounts of alcohol from 

 carbohydrates, and M. rouxii has been used for the commercial 

 production of alcohol. 



Penicillium glaucum 



Penicillium belongs to the Ascomycetes, and bears conidio- 

 phores. Penicillium glaucum forms the bluish-green mouldy 

 patches familiar to every one. It is by far the commonest of all 

 species, and may be obtained from moist bread or jam or by 

 exposing a gelatin plate to the air for a short time. If the mouldy 

 patch be rubbed a fine greenish dust comes away. This dust 

 consists of myriads of spores ; if a little of it be transferred with 

 a moistened needle to a gelatin plate, or, better still, to a hanging- 

 drop preparation, the growth of the organism can be studied. 

 After two or three days little white specks will be observed, which 

 microscopically are found to consist of tufts of delicate interlacing 

 hyphse ; these, becoming interwoven, ultimately form a tough 

 mycelium. The patches of growth are circular, and the hyphse 

 will be found to radiate from the centre. As the patch increases 



