18 XO I Journal of Mycology |Vol. 14 



April 12, giving rise to abundant pycnia April 24, but injury to 

 the leaves prevented formation of acia. 24 



18. Gymnosporangium globosom Farl. Teliosporic ma- 

 terial collected as in the previous instance was sown on the 

 Wealthy variety of Mains Mains April 12, giving rise to a few 

 pycnia April 30, and afterward to aecia first observed July 12, 

 although appearing much earlier. 24 



19. Gymnosporangium Nelsoni Arth. Teliosporic ma- 

 terial on Jnniperus scopulorum Sarg., collected at Boulder, Colo. r 

 by E. Bethel, was sown on Amelanchier intermedia Spach {A. 

 Botryapium DC., as given in Britton & Brown's Illustrated 

 Flora), April 16, giving rise to pycnia April 25, but further de- 

 velopment stopped by injury to leaves. 



Another collection made at the same place two weeks later 

 by Mr. F. D. Kern was sown on A. Canadensis (L.) Medic, 

 (plant from the Arnold Arboretum), April 30, giving rise to 

 pycnia May 8, and aecia May 29. Another sowing was made 

 on another plant of the same sort May 15, which gave a great 

 abundance of pycnia May 22, and a fine development of aecia a 

 month later, June 24. The above cultures were on leaves only. 

 The same material was now sown on both leaves and fruit of 

 Amelanchier erecta Blanch, (plants received from Edw. Gillett, 

 of Southwick, Mass., under name of A. Canadensis, but identified 

 by Mr. W. H. Blanchard as typical A. erecta), May 13, and gave 

 pycnia on upwards of thirty fruits and many leaves May 20, and 

 the first aecia June 5, reaching full and normal maturity June 24. 

 Another sowing was made on leaves of Sorbns Americana May 

 15, which gave rise to pycnia in fair amount May 21, and nor- 

 mally formed aecia, especially on the rachis and midribs, June 24. 



The above results confirm and much extend the somewhat 

 uncertain work of last season. 26 It leaves no further doubt that 

 Roestelia Nelsoni Arth. should be counted a synonym of G. 

 Nelsoni Arth., as suggested in the original publication of the 

 name. 



20. Gymnosporangium clavipes C. & P. Teliosporic 

 material on Jnniperus Sibirica Burgsd., obtained at Lake Forest, 

 111., by Mr. F. D. Kern, was sown on leaves of Amelanchier inter- 

 media April 10, giving rise to a few pycnia May 1, but without 

 maturing aecia. Another sowing was made on fruit of A. erecta, 

 also giving rise to a few pycnia June 5, but not maturing aecia. 

 Checking of development was doubtless due in both instances to 

 inherent weakness of the hosts. A sowing was made on Mains 

 coronaria and Cataegus sp., with no infection. 



"For previous cultures see Jour. Myc. r^:13. 1906; jj:200. 1907. 

 25 For previous cultures see Proc. Am. Acad. Sci. 22 :263. 1887 ; Bot. 

 Gaz. 14:167. 1889; Jour. Myc. i?:200. 1907. 

 28 See Jour. Myc. 7^:203. 1907. 



