. Dedication papers : scientific papers presented at the dedication of the laboratory building and plant houses, April 19-21, 1917. learly, especially where Dodge, B. O. Report on further cultures of Gymnosporangia. Paper readat the December meeting of the Botanical Society of America, New York, 1916. DODGE: STUDIES IN THE GENUS GYMNOSPORANGIUM 135 leaves have been fixed at a time when the sorus is fully matured. Themycelium is confined to the leaf bearing the sorus and does not ordi-narily invade the stem at any point along the line of large cells surrounding the leaf vein appe
. Dedication papers : scientific papers presented at the dedication of the laboratory building and plant houses, April 19-21, 1917. learly, especially where Dodge, B. O. Report on further cultures of Gymnosporangia. Paper readat the December meeting of the Botanical Society of America, New York, 1916. DODGE: STUDIES IN THE GENUS GYMNOSPORANGIUM 135 leaves have been fixed at a time when the sorus is fully matured. Themycelium is confined to the leaf bearing the sorus and does not ordi-narily invade the stem at any point along the line of large cells surrounding the leaf vein appear to prevent the my-celium from entering the phloem of the stem. At the point where the sorus is to be developed, we find a well-defined pseudo-parenchyma, the cell walls taking the orange upper cells of this pseudo-parenchyma are somewhat enlargedand elongated. These are likewise binucleated. They soon beginto swell, lose their cytoplasm, and the nuclei degenerate. In order toshow these upper cells in this condition the material must be fixed atthe earliest possible time that an infected leaf can be distinguished,. Fig. I. Section of a sorus of G. iramformans on a leaf of the southernwhite cedar at the narrowest portion of the young sorus. The epidermis is brokenup on either side, only traces of the cuticle and fragments of the cell walls beingvisible. At the center epidermal cells are still visible. A number of buffer cellsin various stages of degeneration can be seen, and binucleated teleutospore budsgrowing through the buffer cells are common. that is, when a spot appears as a slight, waxy, translucent, light orangeblister. In such cases the epidermis may not have been rupturedand fixation of the mycelium is not apt to be of the best, unless theleaf is cut through. The upper cells mentioned become mere bladderysacs and during this process of swelling the inner walls of the epidermalcells, and hypodermal cells when present, are broken down either byenzyme action o
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectplants, bookyear1918
