ASCOMYCETES. 3 



asci push up between the paraphyses. It is yet an open 

 question as to whether this differentiation of liyphae is 

 universal. Sexual reproduction is unknown in the Asco- 

 niycetes. 



Secondary forms of reproduction. In addition to the 

 formation of ascospores — spores formed in asci — other special- 

 ised reproductive bodies, collectively known as conidia, are 

 present in some species, and usually precede the formation of 

 ascospores. 



These conidia-producing structures are very variable in 

 form in different species, and in some instances more than 

 one form is contained in the life-cycle of a species. Many 

 such conidial forms belonging to the Ascomycetes were at 

 one time considered as distinct sj>ecies, and found a place in 

 the Hyj thorny cetes or the Melanconieae ; in fact it may be 

 assumed, from analogy, that all the so-called species included 

 in the two last-named groups are in reality only stages in 

 the life-cycle of the higher fungi, and mostly belonging to 

 the Ascomycetes. 



Asci. — The asci, or mother-cells of the spores, as already 

 explained, are the specialised tips of ascogenous hj^phae, and 

 when fully formed vary in form in different species, being 

 cylindrical; clavate or club-shaped; or more or less broadly 

 Gbovate. The apex may be rounded without any contraction ; 

 more or less narrowed ; or truncate, that is, more or less flat- 

 tened. In some species the basal portion of the ascus below 

 the spore-bearing portion is considerably narrowed and elon- 

 gated, when it is said to be stipitate. 



When the spores are mature, they are ejected from the 

 ascus, in some species with considerable force. At this stage 

 the wall of the ascus and the protoplasm not used up in the 

 formation of the spores absorb water and increase in size, 

 especially near the apex, at which point the spores collect. 

 When the wall of the ascus reaches the maximum of exten- 

 sion it ruptures at the point of least resistance — the apex — 

 the elastic wall of the ascus contracting at the same moment 

 from below upwards, the contained spores, along with the 

 water, being ejected in a mass. The empty ascus, still fixed 

 at the base, then collapses. The apical portion of the wall of 



b 2 



