314 



Mycologia 



bristle spores. Lindau 11 illustrates the spores with two or three 

 bristles at each end. 



Sappin-TroufTy 16 in his studies of this parasite has failed to 

 observe the presence of bristle spores. Underwood 20 refers to 

 the spores as similar to Ascochyta and A din one ma which are 

 without bristle appendages. Blodgett 2 illustrated this parasite on 

 the carnation rust but did not observe the presence of bristle 

 spores. 



I have failed to find the presence of bristles on young or mature 

 spores of this parasite growing on the three species of rust I have 

 studied. In this respect the form I have studied would agree 

 with the original description of Castagne and Bivona. It is pos- 

 sible that another form appears similar to this species but with 

 bristle spores, in which case it should be considered as a new 

 species. A monograph of this genus undoubtedly would clear up 

 the inconsistency with respect to the morphology of the spores. 

 The bristles may be present only with young spores as indicated 

 in the species Darluca Bivonae Fuckel as Allescher 1 reports the 

 young spores possess bristle ends but absent with mature spores. 



Saccardo 16 lists Darluca Sorghi Zimm. as a parasite on Puc- 

 cinia purpureae without bristle spores. This species agrees with 

 Castagne's original description as well as with the form I have 

 studied. 



The pycnidia vary somewhat in size on the three species of 

 rust I have studied but agree with the measurements of other 

 authors. Castagne says the spores vary from two to three celled 

 but the three celled are rare. Slight variations in the spores are 

 found but not so great as to designate them as separate species. 

 I have found the spores uniformly two-celled. Saccardo gives 

 the following measurements: Darluca filum, 3 to 4x15 to 18//,; 

 Darluca Sorghi, 4 to 13X16/X. The following spore measure- 

 ments I have taken from fresh material: Darluca filum (Biv.) 

 Cast, on Peridermium Peckii, 3 to 4x13 to 19^; Darluca filum 

 (Biv.) Cast, on Coleosporium delicatulum, 3 to 7x10 to i6/a; 

 Darluca filum (Biv.) Cast, on Puccinia graminis, 3 to 7x12 to 



16 fX. 



State College, Pa. 



