REVISION OF ENDOGONEAE. 321 



The spores vary considerably in color, even in the same individual; 

 and although sometimes nearly opaque, "atro olivaceis vel atris," 

 may, when produced free to the light and air, have a decidedly pale, 

 yellowish color. Their outline is characteristically oblong, elliptical 

 to oval or even subpiriform, rarely nearly circular in outline, except 

 when viewed end on. They may be more than twice as long as broad, 

 e.g. 125 X 55 ix, and ordinarily show a decided diiTerence between 

 the long and short diameter; the average variation being from 50- 

 125 X 45-70 11. The wall, although thin as compared with some 

 forms of E. macrocarpa, for example, is thick, 2-4 /jl, in contrast to the 

 walls of the sporangial types. Bucholtz makes a separate category, a 

 fourth subdivision of the genus, to include this somewhat thinner 

 walled type of spore, and speaks of them as possible sporangia. Hav- 

 ing examined a large series of specimens in all stages of development, 

 and from widely separated localities, it seems evident that they are 

 certainly nothing more than chlamydospores, having somewhat thinner 

 walls than those of the more familiar species, and being distinguished 

 by a septum. The attachment of the spore is often sublateral, as is 

 indicated in figure 97 of Bucholtz, and the sporogenous hypha is 

 often, though by no means invariably, somewhat narrower just below 

 the point of attachment. 



The contents of the spores may be rather dense and uniformly 

 granular, or is often somewhat stringy in appearance apparently from 

 the presence of fatty crystalline structures. The species is most 

 nearly related to E. pulvinata and the other forms in which the spore 

 is distinguished by a basal septum. 



Endogone reniformis Bres. 



(Figs. 60-71.) 



Bresadola (1896), p. 297. 



Endogone ? argentina Spegazzini (1899), p. 300. 



Through the kindness of Professors Lindau and Spegazzini I have 

 been able to examine the type material of E. reniformis Bres. collected 

 by MoUer in Brazil and of E. argentina collected at Santa Catalina, 

 Llavallol, Argentina. The Abbe Bresadola has also sent me a third 

 specimen collected by Rick in Brazil, and I myself found apparently 

 the same form in the antarctic forest at Punta Arenas, Magellanes, 

 Chile. 



