4J)0 REi'ou'r OK I'liK iM V('()i.»h;ist of the 



upon the results of this experiment and upon the common obser- 

 vation of florists that i^omc plants refuse to tako rust even when 

 standing close to other plants badly infested, he stated it as his 

 opinion that rust gains access to the carnation plant only when it 

 is very young. Andrew Meyer* tried to infect some of the older 

 varieties with rust aiul they failed to take it. Hinze's White 

 tU)urished for two mouths among rusty Creightous and did not 

 show rust. At the Boston meeting of the American Carnation 

 Society Dr. Halstedf stated that he had produced rust by artifi- 

 cial inoculation of the leaves but he hesitated to say that Dr. Bes- 

 .sey was wrong. AVm. StuartJ inoculated healthy plants with rust 

 spores. " Fiv(^ weeks later microscopi* examination of the tissues 

 <>!' the plants in the vicinity of the inoculations detected the 

 presence of the mycelium in several cases. These were all cases 

 in which the epidermis of the plant had been broken by needle 

 ])uncture. In no case where this was not done was the mycelium 

 found. No sori were found, the time being too short." The 

 name of the variety upon which the tests were made is not given. 



It will readily be seen that it is very important to know 

 whether Dr. Bessey's idea is a correct one. If it is correct, all 

 spraying and other application of fungicides to the foliage is use- 

 less ex])ense and an entirely different line of treatment is neces- 

 sary. In reply to a letter of inquiry, Dr. B^ssey said that he did 

 not know what was the variety he had tried to inoculate. The 

 variety used in such a test is important because we now know 

 that varieties diller greatly in their susceptibility to rust. 



To test the matter for myself I made an experiment on two 

 apparently healthy plants of Daybreak, a variety known to be 

 very susceptible to rust. The plants, about six inches in height, 

 were in 3-inch pots. May G they were thoroughly sprayed with 

 water into which had been previously stirred a considerable 

 quantity of fresh rust spores. The plants were then placed under 

 a bell-jar and kept moist for 41 hours, the temperature of the 

 room meanwhile being about 26^ C. (79° Fahr.). When re- 



* Mever, Andrew. Am.Flr.rist. Vol. VII..P. 807. w a- i *h« 



t Hal>»ted B !>.. Proc, lih .\nii. MeHtingr Am. Carnation Soc. IhO-., pp. fib and 6., In the 

 discussion followinKhis paper, How to Diolinguish Fungus Diseases of Carnations. 

 4:8th Ann. Rept. Vermont E.xp. Sta., 1894, 117. 



