324 



1915) conducted an extensive investigation of this species in comparison 

 with G. transformans. In connection with this work he repeatedly 

 obtained infection by using telia from galls on Chamaecyparis thyoides, 

 on A. canadensis, A. intermedia and A. Amelanchier which resulted in 

 the development of Roestelia Botryapites. (c. f. 27). He failed to obtain 

 any infection on Aronia. 



21. Gymnosporaxgium clavariaeforme (Jacq.) DC. Fl. Fr. 2:217. 

 1895. 



Tremella clavuriaef ormis .Jacq. Coll. 2:174. 1788. 

 On Malaceae: I. 



Amelanchier canadensis (L.) Medic, Felton, .June 8, 1893, F. D. 

 Chester. 



The alternate host for this species occurs on Juniperus communis 

 L. and ./. sibirica Burgsd. 



Oersted (Overs. Vid. Selsk. Forh. 210, 1867; Bot. Zeit. 222, 1867) 

 was the first to carry out infection experiments with this species. He 

 successfully infected Crataegus oxycantha following sowings with telial 

 material. This species has since been frequently cultured by European 

 investigators and the results have been fully summarized by Klebahn 

 (Die Wirtswechselden Rostpilze 339-345. 1904). 



In America, Thaxter (Proc. Am. Acad. Sci. 22:262. 1887; Bot. Gaz. 

 14:166. 1889) was the first to conduct definite cultures. He succeeded 

 in obtaining the development of an abundance of pycnia and aecia on 

 Crataegus tovientosa and Amelanchier canadensis. 



Dr. J. C. Arthur (Jour. Myc. 14:19. 1908) in 1907 succeeded in 

 obtaining infection of Amelanchier intermedia following sowings of 

 sporidia from Juniperus sibirica with development of pycnia only. In 

 1908 (Mycol. 1:239. 1909) aecia were obtained on Amelanchier erecta 

 following sowings of sporidia from J. sibirica from Colorado. In 1910, 

 (Mycol. 4:24. 1912) using similar infection material, the same author 

 succeeded in obtaining pycnia and aecia on Amelanchier erecta and 

 pycnia on Crataegus punctata. In 1911 (Mycol. 4:56. 1912) the same 

 results on Amelanchier erecta were obtained as in 1910, using telial 

 material from the same locality. In 1913 (Mycol. 7:79. 1915) pycnia 

 were obtained on Crataegus cerronus, following inoculation with telia 

 from Colorado on Juniperus sibirica. 



