388 SECTIONAL TRANSACTIONS.— K. 



constitute the paraphyses. The lower whip-like cells are at first uninucleate, but on 

 further development become multinucleate. These are the ascogonia, and occupy 

 the lower half of the central cavity under the descending curtain of paraphyses. 

 Each of these ascogonia gives rise to one or more hyphse. Nuclei pass into these 

 hyphse from the ascogonia, increase by division, and then associate in pairs while 

 the hyphae become multicellular by septation. The tips then bend over in preparation 

 for ascus formation. This is the highest developmental point of the ascogonia and 

 the hyphse produced by them. They disintegrate just as the paraphyses curtain 

 closes down on them from above. The true ascogenous hyphse arise directly from 

 the vegetative cells at the foot of the cavity. These hyphse consist of a single cell 

 which is generally binucleate. Fusion takes place between two nuclei to give the 

 definite ascus nucleus, and this nucleus divides three times to give the eight nuclei 

 around which the spores form. The spore nucleus again divides and the spore 

 becomes uniseptate. Meiosis takes place during the first two divisions in the ascus, 

 the third being an ordinary vegetative mitosis. 



Prof. Dame H. C. T. Gwynne-Vaughan and Mrs. H. S. Williamson. — 

 Germination of Fungal Spores. 



Considerable difficulty was experienced in germinating the ascospores of Lachnea 

 cretea (Cooke), Phil., and development was first obtained after exposure to bright 

 sunlight. Further experiment showed that the spores are not ripe for germination 

 at ordinary temperatures till eight weeks after they leave the ascus. In younger 

 spores germination can be induced by exposure to heat, the highest temperature and 

 longest exposure being needed for spores newly shed. Ascospores remain viable for 

 four years ; conidia die more quickly, but are capable of germination as soon as 

 produced. They are not killed by freezing. 



Mr. B. Barnes. — On Cultural Varieties of Fungi, produced by heating the 

 Spores. 



Spores of Eurotium herbariorum derived from a stock which has remained constant 

 in ordinary culture since 1922 have been exposed to high temperatures for a short 

 time before sowing, and have then given rise to a number of variants, differing from 

 normal cultures in colour and in form. Some of the variants have retained their 

 peculiar characters through a number of transfers ; others have shown a tendency 

 to revert to the original form ; some have died out. 



Evidence has been obtained that the pigmentation of the sclerotia of Botrytis 

 cinerea may be influenced by similar treatment. 



These results have a possible bearing on the phenomenon of saltation in fungi. 



Mr. James Stirling. — The Occurrence of Monascus on Desiccated Coco-nut. 



The occurrence of this fungus on desiccated coco-nut is noted and its morphological 

 features described. The development of the ascocarp has been followed chiefly in 

 culture in glucose solution, but also in cultures on agar media. The presence of a 

 fusion tube between the antheridium and the trichogyne of the oogonium has been 

 noted, and nuclei have been observed in this tube midway between the two cells. 

 Owing to the minute size of the nuclei and the large number present in the oogonial 

 cell it is impossible to say whether or not fusion of nuclei takes place. Investment 

 by hyphse follows immediately on the passage of the contents of the antheridium into 

 the oogonium, while at the same time the oogonial cell swells and becomes more or 

 less spherical. Short hyphal protrusions, with aggregations of nuclei in their neigh- 

 bourhood, are found round the periphery of this cell, and these give rise to the asci. The 

 asci become spherical, growing at the expense of the central cell, which is crushed. 

 The investing hyphse are at first swollen, and do not completely envelope, but as 

 development proceeds they become flattened and form a thin pellicle round the asci. 



Dr. T. Whitehead. — Phloem Necrosis and Starch Accumulation in Potato 

 Leaf -roll. 



The phloem of healthy and leaf -roll material of twenty varieties has been examined, 

 and necrosis found to occur in all diseased specimens and not in healthy ones. 



