REVISION OF ENDOGONEAE. 337 



however, that there appear to be no other synonyms, and that, al- 

 though several other species of Glaziella have been listed, the genus 

 remains monotypic. 



A final opinion with regard to its true relationships can hardly be 

 formed until the nature of the primary vegetative and sporogenous 

 hyphae is known. It seems not impossible that, like Sclerocystis, it 

 possesses two distinct sets of hyphal elements, the ore concerned in 

 sporulation and without septa, the other copiously septate. x\.lthough 

 in Sclerocystis the septate elements seem to be lysigenous, and are 

 designed to free and scatter the sporocarps and spores; and in the 

 present genus, on the contrary, their object appears to be to hold them 

 firmly in a coherent mass which they render esculent and make con- 

 spicuous by raising it above the substratum through a mechanism 

 remotely comparable to that of some phalloids, their ultimate function, 

 namely an effective dispersal of the spores, may be assumed to be the 

 same. 



In both genera, the fact that one element in their structure does not 

 conform to the ordinary phycomycetous type, since it is composed of 

 copiously septate filaments, may be explained by their specialization 

 for a definite purpose other than sporulation. In Sclerocystis at 

 least, the sporogenous element corresponds in structure to that of the 

 Mucorales, since its hyphae are more strictly continuous even than in 

 Endogone. Whether this is also the case in Glaziella cannot be 

 determined till very young material is available for study. The 

 presence of an independent and continuous endospore, Figure 91, like 

 that of the zygospores in Endogone, points to a further possibility of 

 their sexual origin. 



In any case Sclerocystis and Glaziella may be assumed to illustrate 

 the highest degree of differentiation which is reached in the family, so 

 far as it is known; and their structure and development is the more 

 remarkable, when it is contrasted with the relatively simple condi- 

 tions which obtain in other forms. They do not seem, however, to be 

 nearly related, although, if the above suggestion as to the sporogenous 

 element in Glaziella is correct, the dual nature of the elements which 

 compose them and the definite segregation of the sporulating regions 

 are characters in common. The wefts of finer filaments which in 

 Glaziella are associated with spore-origins which might be regarded 

 as corresponding to the sporocarp initials of Sclerocystis, do not, how- 

 ever, seem comparable; since the fine filaments which compose them 

 become closely septate, and seem to arise directly from the inner layer. 



It should be mentioned that all other fungi which have been in- 



