SECTIONAL TRANSACTIONS.—K. 359 
In the first meiotic division, seven and fourteen gemini are counted, and in the 
telophase of the third division, seven chromosomes (the haploid number) are observed ; 
thus indicating the occurrence of two nuclear fusions in the life-history and the 
occasional omission of one of them. 
10. Miss W. M. Pace.—Contributions to the Study of the Lower 
Pyrenomycetes. 
Species of Podospora, Sordaria, and Chetomiwm were grown in culture and fresh 
material and sections examined. The germination of the spores, development of the 
mycelium and perithecium initial, and formation of the spores in the ascus are 
described, together with the growth and heliotropism of the neck with special reference 
to two-necked forms. 
11. Miss E. Green.—Zygorhynchus Meelleri. 
This fungus was found on soil and cultivated on potato-dextrose agar and other 
media. ‘The development of the gametangia, the formation of the zygote, and the 
germination of the zygote and sporangiospore were studied, both in fresh material and 
in section. 
12. Mr. G. B. Wattace.—The Biology of Macrosporium and some 
Allied Genera. 
During the year 1924 isolations (single spores) were made of fungi belonging to 
the genera Macrosporium, Alternaria, and Stemphylium. These were obtained from 
tomatoes showing rots, except in one case, where a Macrosporium was isolated from 
Echium vulgare. 
Several of the forms of Macrosporium and Alternaria isolated exhibit constant 
differences, by which they may be recognised ; for this reason, and in order that 
their relationships might be made clearer, each distinct fungus-form was cultured 
under carefully controlled and reproducible conditions of food and environment. 
At the same time characters of taxonomic importance have been studied. 
Named species of each of the three genera were cultured as controls. 
The subject of saltation was studied, as it was found to occur in representatives 
of each of the genera studied, and might cause confusion later in diagnoses. 
12a. Mr. H. H. Sturcu.—Choreocolax polysiphoniae, Reinsch. 
Saturday, August 29. 
Excursion to Petersfield and Ditcham Park. 
Monday, August 31. 
Morninea. 
13. Dr. A. W. Hitt, F.R.S. — The genus Crantzia, a Study im 
Geographical Distribution. 
14. Miss A. J. Davey.— Seedling Morphology and Anatomy in 
Juglans spp. 
Attention is called to certain morphological differences in the form of the plumule. 
J. regia shows a vertical series of accessory buds above the axil of each cotyledon 
and the first plumular leaves are of the adult foliage type. J. nigra and J. Hindsii 
do not produce accessory buds and the plumule bears a series of about eight scale 
leaves showing transitions to the pinnate foliage leaf. 
Interest centres in the structure of the vascular strands of these scale leaves in 
J. nigra. At the node each leaf trace consists of two vascular strands separated by 
parenchyma in which isolated central protoxylem sometimes occurs. The traces of 
