26G STATE HORTICULTURAL SOCIETY. 



agencies to the leaves of the barberry. The fungus now grows for a time in the 

 barberry leaf and then breaks out on its surface in the form of slender, conical 

 bodies of a yellowish color, filled with numerous light spores which, upon the 

 rupture of the sac containing them, are borne away by the winds, it may be for 

 many miles, and, falling upon wheat or other grasses, germinate and })rbduce 

 the nist again. This curious change of hosts, first the wheat, then the 

 barberry, and finally the wheat again, is repeated from year to year, the barberry 

 apparently being an essential factor in the process without which the rust 

 would fail to maintain its succession of generations. Strange and even 

 improbable as this succession of diflferent generations on such Avidely different 

 plants may appear, it is nevertheless accepted as the veritable history of this 

 fungus by highly competent scientists, and recent experiments go far to 

 confirm their belief.* 



Still it must be remembered that in such an inquiry mathematical demon- 

 stration is out of the question, and every additional fact tending to throw light 

 upon the question, in whosoever possession it may be, ought to be recorded as 

 contributing to a more perfect knowledge of this ditficult subject. The prac- 

 tical bearing of the case is at once apparent. If it is admitted that Puccinea 

 gi'aminis, the wheat rust, is simply one of the stages of ^cidium lerhtridis 

 the barberry fungus, we have a comparatively worthless shrub growing far 

 and wide over the country, slightly diseased from time to tinie, and communi- 

 cating this disease in an altered form to the wheat crop, and the fact that sci- 

 entific evidence accumulated through many years points to this conclusion 

 should be sufficient to lead to the extermination of the common barberry. 



A red rust, Uredo luminata, frequently occurs upon the leaves of raspberry 

 bushes, both wild and cultivated, and has sometimes been so prevalent as to 

 seriously injure the plants afiected by it. The botanist of the State of New 

 York in his report for 1874 mentions the fact of its rapidly becoming a pest 

 to the cultivators of blackberries and raspberries. It is not uncommon in 

 Michigan, though I am not aware that it has yet proved particularly destruc- 

 tive here. 



Another rust, Melampsora populina, occurs on the leaves of different species 

 of poplars, breaking out in orange yellow spots which afterwards become dark 

 brown or nearly black. It is said to have done much injury to cottouwoods in 

 the west, particularly in Iowa. Still another species of rust known as ^cidium 

 pint, attacks the young plants of Scotch pine and other species of pine in 

 nurseries, and sometimes occasions much damage. 



As for the treatment of plants affected by any of the different rusts, it is 

 probable that flowers of sulphur, prepared and applied in the way already 

 described, would prove a satishictory remedy. In those cases where therestiug- 

 spores remain in the leaf and fall with it to the ground, the gathering and 

 burning of the fallen leaves in the autumn would be a useful precaution against 

 the further spread of the disease the following year. 



The smuts previously mentioned in connection with the rusts are nearly all 

 parasitic upon herbaceous plants. Corn smut is one of the best known, and 

 the smut of wheat, oats, and barley will also occur as familiar examples. They 



♦Experiments conducted during tlic present year in ICngland, are thus described by Mr. 0. B. 

 riowriglit, tlie gentleman by wlioni ihcy were carried on: "This yearanotlier series of cultures 

 was instituted, in which the promycelium siiorcs of I'uncinia firamuus were sown upon young 

 barberry planttt with tliu unvarying result of in-oducing the iKcidium, the check plants remaining 

 free from the fungus. Young wheat plants, wliich were kept continuously covered by bell glasses 

 from the time they were first sown till the experiment was concluded, were also fonnd when 

 infected witli ripe ^Jiciditim bcrheridis spores, to become intcctcd with Uredo, while similar plants, 

 not so infected, remained healthy."— [Grevillea, September, 1882.] 



