Showing papers by "Lindsay S. Olive published in 1958"

De Bary Bubbles in Ascospores of Sordaria fimicola

Abstract: At the request of Dr. B. 0. Dodge, whose recent paper on this subject appeared in this journal (1957). I have applied to Sordaria fimicola his technique for producing de Bary bubbles in ascospores and am submitting this note containing my observations on these structures. When Shear's Mounting Fluid (SMF) is added to clusters of mature asci of S. fimicola, de Bary bubbles appear very readily in the ascospores, as described by Dodge for other ascomyeetes. These bubbles reach full size within about a minute after SMF is added, at which time they generally extend across the breadth of the spore, bounded by the inner walls. A single bubble appears in each spore. Spores dried in the air very quickly develop similar bodies. These bubbles undoubtedly add to the buoyancy of the spores as they are discharged from the asei. When spores dried in air or treated with SMF are returned to water, the bubbles disappear in a minute or so. If the spores are again transferred to SMF the bubbles reappear. The components of the mounting fluid (glycerine, alcohol, potassium acetate in aqueous solution) either do not enter the spores or do so in nontoxic concentrations, for spores transferred to water and then to agar after several minutes in SMF germinate readily. When hybrid asei containing four gray and four wild-type ascospores are placed in SMF, de Bary bubbles appear only in the wild-type spores, while the gray spores collapse (fig. 1). The latter, which normally germinate somewhat earlier than wild-type spores, probably have less resistant walls. Immature spores, like the gray ones, fail to form de Bary bubbles. There has been some question among observers as to the nature of these structures within treated spores. Since the present experiments have shown them to be decidedly of a gaseous nature, I have not hesistated to call them bubbles. They have the characteristic dark periphery and light center. But even more convincing is the fact that when pressure is firmly applied to the cover slip so as to crack the spore walls, the bubbles may be foreed out into the mounting fluid where they disappear at different rates, some within a few seconds after being pressed out, the majority within a minute. Some larger ones formed by coalescence gradually diminish and disappear after several minutes. If the spore wall is cracked gently so as to retain the bubble within the spore, the bubble disappears rather rapidly in situ. Some spore clusters were transferred from SMF to mineral oil and ma-