240 TEXT-BOOK OF FUNGI 



conidia only, produced either in perithecia or on naked 

 conidiophores. Some have been proved to be conidial 

 forms of the higher fungi, and the remainder are suspected 

 to belong to the same category. Deuteromycetes. 



PHYCOMYCETES 



In most systematic works a fundamental characteristic 

 of the present order is said to be the absence of transverse 

 walls or septa in the hyphae. How this -misconception 

 could arise in the first place is difficult to understand, and 

 why it is continued in quite recent works passeth all 

 understanding. Perhaps the statement is intended to 

 apply to the primitive or the sexual phase only. In Proto- 

 myces, a very simple type, the hyphae are very distinctly 

 septate. The same is true of Dispyra, and Thaxter has 

 pointed out their presence in Dimargaris. Septa are often 

 abundant in the vegetative hyphae of Mucor, etc., and 

 when we come to the conidiophores of aerial forms, septa 

 are very frequently present. The instances given do not 

 apply to the formation of septa just prior to the develop- 

 ment of antheridia, oogonia, chlamydospores, etc. 



On the other hand, many species are aseptate until the 

 organs of reproduction are formed, agreeing in this respect 

 with Vaucheria, and some other algae. 



In the family Apodyeae of Fischer true septa are absent, 

 but there is a characteristic segmentation of the hyphae 

 indicated by constrictions due to the deposit of a substance 

 called cellulih, which nearly closes the lumen of the hypha 

 at the point of constriction, only a small central pore 

 remaining open, through which the protoplasm passes. 



