i9i 2] WOLF—ACTINONEMA ROSAE 233 



Angevine, Triomphe d'Alenfon, Abel Grant, Rosa borboniaria 

 var. Triomphe d' Anger, of the 600 growing in the botanical 

 gardens at Pavia are free from the attacks of this fungus. Laubert 

 and Schwartz 29 call attention to the fact that the bushy sorts are 

 more susceptible than climbing varieties, and also that thin- 

 leaved species are most liable to attack. Halsted 30 finds that a 

 wild species, Rosa humilis, is also subject to attack when growing 

 in a garden with diseased plants. The amount of loss caused is 

 equaled or surpassed by only one other rose disease, the powdery 



mildew. 





Control measures 



the 



compounds. Since 



the fungus winters over in the fallen leaves, sanitary measures may 



better be employed in combating the disease. . If all the leaves 



are gathered together and burned either late in the autumn or 



early in the spring, before the new leaves have expanded, the 



chances of infection would be greatly lessened. 



This investigation was undertaken at the suggestion of and 



under the careful direction of Professor George F. Atkinson, 



Cornell University, to whom I am very grateful for help and 

 criticism. 



Agricultural Experiment Station 



Auburn, Alabama 



Note. — Since this manuscript has been sent to the publishers, I have 



received type specimens of Asterella rubi, which had been sent to Professor 



George F. Atkinson, through the courtesy of Professor F. von Hohnel. 



Because of the fact that Asterella rubi is the first Asterella to be connected with 



an Actinonema, and is one of the most recently described species of this genus, 



it is especially important that it be compared morphologically, with the rose 

 fungus. 



For the study of the structure of the fruit bodies of Asterella rubi the 

 cortex of some of the affected raspberry canes was imbedded in paraffin and 

 sectioned. The perithecia w T ere found to possess a central pore or ostiolum. 

 They are entirely superficial and with a well developed structure only on the 

 upper side. There is no well defined stroma from which the asci arise. 



By treating small pieces of the cortex with lactic acid the entire shield may 



29 See footnote 22. 



30 Halsted, B. D., New Jersey Agr. Exp. Sta. Rept. 13:281. (1892) 1893. 



