50 



SCIENCE. 



[N. S. Vol. XXII. No. 550. 



Angelli, holding it to be distinct from Viola 

 palmata, the differences showing in the char- 

 acter of the flowers and of the summer leaves. 

 Miss Angell, who was present, told of her 

 studies of this species and called attention to 

 the extraordinary size of the summer leaves. 

 Dr. Rusby in the course of his remarks men- 

 tioned a very early form which is apparently 

 the variety cordata of Viola cucullata of Gray. 

 This form has been studied extensively by 

 Miss Sanial, one of the club members. 



Dr. Rydberg spoke of the violets of the 

 Rocky Mountain region, passing in review the 

 various species from that section and calling 

 attention to the occurrence of the common 

 European Viola hifiora which reappears in 

 Colorado. 



Dr. ShuU spoke of the difficulty he had ex- 

 perienced in germinating violet seeds, and in 

 the discussion it was brought out that violet 

 seeds are apt to lose their vitality upon drying. 



Dr. MacDougal spoke of the difficulties at- 

 tendant upon mutation experiments with the 

 violets, and advocated experiments to test any 

 possible theories as to hybrids. 



After some further discussion by Dr. Brit- 

 ton and others this most interesting meeting 

 was brought to a close. 



Edward W. Berry, 



Secretary. 



THE UNIVERSITY OF COLORADO SCIENTIFIC 

 SOCIETY. 



During the academic year 1904-5 the so- 

 ciety met every Monday evening from Oc- 

 tober to May, holding in all thirty meetings. 

 In nearly all cases a single topic was discussed 

 at each session, but a few times there were 

 two papers given. The speakers avoided tech- 

 nicalites as far as possible and presented 

 their topics in such form as to be interesting 

 to men of science generally. Papers were 

 given, for the most part, by members of the 

 faculty representing the various departments 

 of pure and applied science. At the last meet- 

 ing of the year, held on May 15, the following 

 officers were elected: 



President — Henry B. Dates. 



Y ice-President — Ira M. DeLong. 



Secretary — Francis Ramaley. 

 Treasurer — Martin E. Miles. 



Francis Ramaley, . 

 Secretary. 

 BouLDEE, Colo., 

 June 7, 1905. 



SPECIAL ARTICLES. 

 NEW WORK UPON WHEAT RUST. 



For a number of years it has been the belief 

 of the writer that the efficiency of the uredo- 

 spores (summer spores) of wheat rust to per- 

 petuate the disease is possibly much greater 

 than thought to be. It has been assumed by 

 most botanists that these spores are quick to 

 germinate and short of life. ' As there are 

 formed definite resting spores, and also the 

 cluster cup stage on the barberry bush, it has 

 been apparently taken for granted that the 

 summer spores have no other effect than to 

 rapidly spread the disease from plant to plant 

 during the summer season. 



It will be interesting news to mycologists to 

 know that we have at last definitely estab- 

 lished the fact of the wintering of the red 

 spores (uredospores) of a number of the im- 

 portant rusts in viable form, including the 

 important species Puccinia graminis. 



During the winter of 1888 and 1889 the 

 writer, while working at the Indiana Station, 

 first demonstrated the fact that the mycelium 

 of the uredo stage (red spore stage) of the 

 species known as Puccinia rubigo-vera could 

 pass the winter in the tissues of the wheat 

 plant uninjured (see Agricultural Science, 

 Vol. 3, page 105). During the summer of 

 1890 (see Agricultural Science, Vol. 5, Nos. 

 11 and 12) it was further proved that the red 

 spores of this last-named species could survive 

 exposure to the drying air and sunshine of 

 July and August for over a month. This in- 

 dicated that it was possible for such spores to 

 be borne many miles by the wind, and aided 

 to an understanding of the rapidity with which 

 general rust infection may take place over 

 large areas of country. 



Aided by the persistent and painstaking 

 efforts of assistant plant pathologist Mr. F. 

 J. Pritchard, I have at last been able to make 

 numerous trial studies upon methods of stor- 



