NEW LITERATURE. 



45 



NEW LITERATURE. 



BY W. A. KELLERMAK. 



Farlow, W G. — ''Notes on some species of Gymnosporangium and 

 Ch ry somy xa of the United States;'' in proceedings of the American 

 Academy of Arts and Sciences, communicated Feb. 11th, 1885. 

 Dr. Farlow gave an account, in a paper on ''The Gymnosporangia of 

 the United States," published in the Anniversary Memoirs of the Bos- 

 ton Society of Natural History in 1880, of his unsuccessful attempts to 

 show, by means of cultures, the rel itionship of the Gymnosporangia to 

 the forms of Boestelia growing near Boston. The present paper details 

 continued and more extensive experiments of a similar character made 

 in May and June, 1883. "The method of culture employed was the 

 following : Specimens of different species of Gymnosporangium were 

 gathered early in May, before the spores had begun to germinate, and 

 while the spore masses were flat and not swollen into gelatinous pro- 

 tuberances, as is the case when they are moistened by showers. The 

 specimens were then placed in watch-glasses under moistened glasses, 

 each species by itself, when the spore masses soon expanded, and the 

 spores began to germinate. It was in this way easy to arrange so that 

 the spores of the different species were kept pure,— a fact confirmed 

 by microscopic examination. As the spores germinated, the sporidia, 

 of a bright orange color, dropped into the moist watch-glasses, and 

 were used at once for infecting the desired plants. Two kinds of ma- 

 terial were used. The first consisted of leaves of different Pomacece, 

 which were freshly gathered in the Botanic Garden of Cambridge, and 

 at a distance from any species of Juniperiis which could have been 

 infested by a Gymnosporangium. The leaves were placed on moistened 

 glass slides, and arranged on zinc stands under bell-glasses. The spori- 

 dia were then carefully dropped upon the leaves, which were immediately 

 covered by a bell-glass. The leaves under each glass were sown with the 

 sporidia of but one species, and subsequently, when it was necessary to 

 remoisten the slides, the bell-glasses were removed for a moment only, 

 and at no time were the leaves under more than one bell-glass exposed. 

 I abo used a number of small seedlings of Pomacece, each pot being cov- 

 ered by a glass receiver. The seedlings were supposed to be in a healthy 

 condition, but, to serve as a check, a number of similar seedlings were 

 kept on which no sporidia were sown. The young plants were inoculated, 

 either by dropping the sporidia upon them, or, in cases where the leaves 

 were not in such a position to retain drops well, small pieces of the gelat- 

 inous spore masses were placed on them, it first being ascertained that 

 the spores had begun to germinate. After three or four days it was 

 necessary to remove the remains of the gelatinous masses in order to pre- 

 vent moulding. After the lapse of a week, at which period the germinal 



