Notes and Brief Articles 



43 



journals. Some time was also spent in outlining the changes in 

 our ideas of what constitutes a species in the rusts. The dif- 

 ferences of opinion regarding physiological and morphological 

 species were considered. 



Following this paper, I. E. Melhus called attention to his ob- 

 servations on the development of aecia on red clover in the green- 

 house. Although several other clovers grew in close proximity, 

 they remained entirely free from infection. i\ttempts to inocu- 

 late other clovers with the aecia from red clover were unsuc- 

 cessful. 



In the absence of G. R. Bisby, Dr. Arthur outlined briefly the 

 contents of his paper, dealing with the rusts on the Onagra- 

 ceae. Several species have formerly been recognized which have 

 slight morphological variations. These apparent differences, how- 

 ever, become less conspicuous as the number of specimens increase. 

 Mr. Bisby has concluded that these supposed species represent 

 one very variable species in which several races or strains can be 

 separated with very slight morphological variations. 



A paper by W. H. Davis and A. G. Johnson on the aecial stage 

 of the red clover rust was presented by Mr. Johnson. Examina- 

 tion of red clover from a number of fields showed aecia to be 

 present in all except one. A request was then sent out for red 

 clover plants from various localities. Over half of them showed 

 aecia. Teliospores were used to make sowings and from these 

 aecia were again obtained, showing the rust to be autoecious. 



In the absence of E. B. Mains, Dr. Arthur also outlined his 

 paper. Until recently, no species of Melampsora has been known 

 in the Western Hemisphere on Euphorbia. In one year three 

 such species have been reported, occurring from Maine to Wy- 

 oming. One of these was doubtless imported, while the one 

 ofxlirring in Indiana was probably native but identical with a 

 European species. This sudden occurrence of a class of rusts 

 formerly unknown in America in such widely separated localities 

 is regarded as rather a remarkable phenomenon. 



Dr. Arthur, in the absence of Mr. Bisby, also mentioned his 

 paper on the short-cycled species of Uromyces in North America. 

 Also, in the absence of C. A. Ludwig and C. C. Rees, the same 

 speaker made a brief mention of their work on the structure of 

 the uredinium in Pucciniastrum Agrimoniae. 



