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Excerpt from A Disease of Pines Caused by Cronartium PyriformeThe type material P. pyriforme was not accessible at the time the article was prepared, as all of Pecks specimens were packed up and in transit from the old to the new quarters of theMoreExcerpt from A Disease of Pines Caused by Cronartium PyriformeThe type material P. pyriforme was not accessible at the time the article was prepared, as all of Pecks specimens were packed up and in transit from the old to the new quarters of the New York State Museum. The writers therefore had to depend upon Arthur and Kerns published statement concerning this species (1, p. 420), The spore measurements also of the typical P. pyriforme did not correspond, since the length of spores of the eastern species as given by Peck in his original description was too great. While this article by the writers (6) was in press, Arthur and Kern published an article (2) in which they discarded their earlier interpretation of P. pyriforme and admitted that there is a species of Peridermium with typical pyriform, obovate, or oblong-pyriform spores, just as Peck had originally described it in 1875 (10), and that then original assignment of P. pyriforme Peck to what is now known as P. comptoniae was an error. They also suggested that the alternate stages of this Peridermium would probably be found on species of Comandra.Orton and Adams (9), in 1914, published an article on Peridermium from Pennsylvania, in which they discussed Peridermium comptoniae and P. pyriforme. They described the finding of a caulicolous species of Peridermium at Charteroak, Huntingdon County, Pa., on the trunks of Pinus pungens, which proved to be the true Peridermium pyriforme of Peck. Subsequently Cronartium comandrae was found within 40 feet of the infected pines and the conclusion reached that this Cronartium is the alternate stage of Peridermium pyriforme. They also state that P. betheli is probably a synonym of P. pyriforme. In May, 1914, Arthur and Kern in a general discussion of the North American species of Peridermium inhabiting pines (3) gave the synonymy of P. pyriforme, a technical description, and an explanation of their change of opinion regarding the species.In June, 1914, the writers published culture data (8) showing that successful sowings of the aeciospores of Peridermium pyriforme had been made on Comandra umbellata, thus completing the life cycle of this interesting rust and proving that its alternate stage was the Cronartium found on Comandra.Morphology Of The Fungus.The macroscopic characters of Peridermium pyriforme are practically identical on all the hosts examined by the writers, but there are some differences in the microscopic characters, especially in the shape and size of the aeciospores. This difference in size and shape of the spores may be due to the influence of the aecial host- that is, they may vary according to the species of Pinus which the Periderrium inhabits.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully- any imperfections that remain are intentionally left to preserve the state of such historical works.