Miles : A New Myriangium on Pecan 



79 



the irregular rupture of the ascus wall. Each ascus contains eight 

 spores. There are no paraphyses. 



The locules average 50 x 50-50 x 60 /x while still in position in 

 the stromal When freed they become more oval in form, probably 

 due to the expansion of the ascus on absorbing water, when they 

 average 62-65 x 40 fi. The ascus entirely fills the locule, but after 

 the rupture of the sheath has occurred it becomes 90-95 ^ in length, 

 contracting but little at its broadest part, the middle, but consider- 

 ably toward each end. 



The spores are multiseptate-muriform, large, oblong, and straight 

 or sometimes slightly curved. They are seven- to eight-septate, 

 with the middle septum much more definite than either of the 

 others. There may be a slight constriction at either of the cross 

 septa, but it is always more pronounced at this middle septum. 

 The longitudinal septations are irregular, as are the others, with 

 the exception of the middle one, dividing the spore into irregular 

 somewhat cubical portions. When observed from the end in opti- 

 cal section the spore appears to be built about a very small, hollow 

 central core, the segments being arranged about this very much in 

 the manner of the grains on the cob of an ear of corn, when it, 

 likewise, is observed from the end. The segments, however, are 

 much fewer in number than in this latter case, the average number 

 about the central core being 5 to 7. The spores average from 

 25-28 fx in length by 10-11 ^ in breadth. They are ordinarily 

 observed to be hyaline, but in quite mature specimens they have a 

 very faint yellowish tint. 



Identity 



The morphology of the fungus, especially the character of the 

 indehiscent, monoascicular loculi scattered throughout or rather 

 grouped toward the periphery of a pseudoparenchymatous stroma 

 point at once to the family Myriangiaceae. The resemblance of 

 members of this family to the Tuberales has been pointed out by 

 Saccardo and Engler and Prantl. They exclude them from that 

 order on account of their aerial, parasitic or saprophytic habit, and 

 their general appearance. Von Hohnel monographed this family 

 in 1905 and places it in the Discomycetes close to the Tuberales. 



