Morphology. 3 1 



in detail under the various groups to wliicli tLej 

 belong. At present it will be sufficient to state that the 

 spore-like bodies called gonidia may be produced in a 

 mother-cell by free cell-formation. In such cases the 

 mother-cell is called a sporangium, and is at least 

 analogous with an ascus, and the contained gonidia 

 analogous with ascospores. In some genera belonging 

 to the Fliy corny cetes, as PhytoptJiora, Cystopus, and 

 Achlya^the gonidia on their escape from the sporangium 

 possess the power of spontaneous movement for alimited 

 period, and are called swar?n-$pores, zoospores, or 

 zoogonidia, on account of their animal-like movements. 

 In the Ascomycetes the gonidia are almost always pro- 

 duced at the tips of slender hyphal filaments, which 

 either remain short, densely crowded, and contained 

 within a pseudo-cellular coveriDg, or remain naked, 

 that is, not contained within a special covering, and in 

 this case the hypha3 are frequently much branched. 

 To this last type belong most of the forms popularly 

 known as moulds, but it must be borne in mind that 

 the term mould has no scientific value, and also in- 

 cludes many forms of gonidia produced in sporangia, 

 as in Mucor. In the Phy corny cetes and Ascomycetes the 

 gonidial stage often precedes the ascosporous con- 

 dition, but in numerous instances in the same groups 

 the two phases develop simultaneously. Until 

 recently gonidia were considered rare in the large 

 division of tlie Basidiomy cetes. Brefeld, however, has 

 shown that in this group gonidial forms are as general 

 and as various in structure as in any other group, and 

 may develop as independent structures or spring from 

 the basidia producing sporophores. The hyphaa 



