xv.] MOULD-FUNGI. 201 



dependent on such acclimatisation, and are not ordinary 

 moulds, but a distinct species of aspergillus (Lichtheim), which 

 grows well at higher temperatures (38 to 48 C.), and the 

 spores of which under all conditions of growth are capable 

 of producing in rabbits the mycosis in question. 



(c) Penidllium. In this fungus hyphae, which are not 

 septate, grow out from the mycelium ; from the end of each 

 of these arise like the fingers of the hand a number of short 

 branched cylindrical cells, which give origin to chains of 

 spherical spores. 



The following two fungi belong to the order of fungi 

 called Phy corny cetes. 



(d) Mucor is characterised by this, that from the mycelium 

 hyphae grow out which are not septate, and at the end of 

 these a large spherical cell originates, sporangium, in which 

 by endogenous formation a large number of spherical spores 

 are developed ; the wall of the sporangium giving way, the 

 spores become free. 



(e) Saprolegnia ; colourless tubular threads, forming gela- 

 tinous masses on living and dead animal and vegetable 

 matter in fresh water. The cylindrical or flask-shaped ends 

 of the threads xoosporangia form in their interior numbers 

 of spherical or oval spores zoospores, possessed of locomo- 

 tion (one flagellum at each pole) and which finally escape 

 from the threads. These zoospores after some time become 

 resting, surround themselves with a membrane, and finally 

 germinate into a cylindrical mass which becomes transformed 

 into the mycelium. Besides this asexual there is, however, 

 a second or sexual mode of fructification, consisting in this : 

 At the end of a mycelial thread a cell grows up into a 

 spherical large ball, the oogonium. From the same thread, 

 thin threads antheridia grow towards the oogonium, with 

 the protoplasm of which they merge. This latter then 



