133 



242 JL O u Mycologia 



June 15, but did not further develop owing to weakness of the 

 host. 



The aecia of this species have the same horn-like appearance 

 as those of G. cornutum, already discussed, and the two are usu- 

 ally included under the same name. The only culture known to 

 the writer, showing that the form on Sorbus and the similar one 

 on Aronia are distinct, was made by Dr. Ed. Fischer 34 of Bern, 

 Switzerland, and published in November, 1907. On May 29 of 

 that year he made a sowing of teliospores from Juniperus com- 

 munis on Sorbus Aria, S. torminalis, S. hybrid a, S. Aucnparia, 

 Amelanchier Botryapium and Aronia rotundifolia (Amelanchier 

 vulgaris), and obtained an infection only on Aronia. He con- 

 cluded from this result that the form on Aronia is distinct from 

 that on Sorbus, but made no suggestion regarding the nomen- 

 clature. Mr. Kern, 35 however, finds diagnostic characters to sep- 

 arate the forms in both aecia and telia, and has supplied a name. 

 The cultures by Dr. Fischer were not known to the writer until 

 long after the above studies had been concluded. 



23. Melampsora Medusae Thiim., on Populus tremuloides 

 Michx., collected at Boulder, Colo., by Mr. E. Bethel, was sown 

 April 7 on Ribes rubrum, R. Cynosbati and Larix laricina. The 

 only infection was on the Larix, showing pycnia April 14, and 

 aecia April 21. 38 When the sowing was made, it was supposed 

 that the rust in hand was Melampsora albertensis Arth. ; but after 

 the result was obtained a careful inspection of the remaining 

 material of the collection brought to light the fact that while the 

 leaves were conspicuously covered with that rust, they also bore 

 some sori of the more common species, and it is believed that the 

 infection came from the latter, as recorded above. 



Successful cultures reported now for the first time : 

 The following species have never been cultivated, in America or 

 elsewhere, so far as the writer knows. Much credit for the ample 

 results is due to the mycologists who have cooperated in the work 

 by making invaluable observations in the field and supplying suit- 



3 *Archiv Sci. Phys. et'Nat. 24: . Nov. 1907. 

 35 Bull. Torrey Club 35: 507- 1908. 



38 For previous cultures see Jour. Myc. 10: 13. 1904; HI 5 2 - T 905 ; an d 

 12: 13. 1906. 



