SECTIONAL TRANSACTIONS.—K. 363 
(o) Dr. K. BuackBurn.—Apogamy in the Angiosperms. 
Although cross- or self-fertilisation is normal in flowering plants, many forms are 
known in which seeds are produced without the aid of fertilisation. 
This apomixis may be by apogamous development of an embryo from any cell of 
a haploid gametophyte (haploid apogamy), by similar formation from a cell of a 
diploid embryo-sac (diploid apogamy), or by vegetative budding from the nucellus or 
integument. 
There are no uncontested records of the first type in Angiosperms, but many cases 
are described in which the omission of the reduction division (apospory) accompanies 
apogamy ; nucellar budding may also be present in the same ovule and will be con- 
sidered here as if included in diploid apogamy. 
Apogamy tends to occur in polymorphic genera, and is frequently accompanied by 
, polyploidy and pollen sterility. 
Cytological evidence suggests that in Rosa, Hieraciwm, &c., apogamous forms have 
been produced by crossing. Having once arisen these new forms would persist because 
of their apogamy. A further increase of the polymorphism of the genus can take 
place when these forms have some ovules capable of fertilisation or fertile pollen. 
Again bud-sports producing seed may have a similar effect. 
Some segregation has been observed in apogamously produced seedlings in roses 
and other plants; this is easily explicable if meiosis has taken place but otherwise 
difficult to account for. 
(c) Dr. M. Kyiaut.—A pogamy in the Alge. 
1. What is the normal course of sexual reproduction in the Algz ? 
Estimate of the proportionate number of Algz in which sexual reproduction is :— 
(a) Obligate. 
(b) Facultative. 
(c) Not yet determined. 
2. The inter-relation of sexual behaviour with variations in the environment. The 
conditions leading to parthenogenesis. 
3. The position of meiosis in the life-cycle of the Alge and its significance. 
4, General statement on the lack of precision characterising the relationship 
between cytological state and nature of reproductive cells in the Alge. 
(d) General Discussion. 
22a. Mr. J. H. Parxer.—The Inheritance of Winter and Spring Types in 
Barley. 
23. Prof. J. McLean THompson.—Some General Problems of the Anguo- 
spermic Flower. 
The plasticity of the angiospermic flower in species of varied affinity is con- 
sidered. 
Some general problems on the evolution and meaning of modern floral types, which 
these variations raise, are discussed. 
24. Mr. T. A. Spracue.—The Relative Specific Predominance of 
Phanerogamic Families in the Floras of the World. 
Results of floristic analyses of 75 Phanerogamic Floras are given. Each table 
has the Families arranged according to the numbers of their species in that Flora. 
Composite, Leguminose, Graminee and Cyperacee are high in most Floras. 
Certain sets of other Families, termed ‘Indicator Families,’ are high only in 
particular types of Flora. Four main types are recognised. 
1. Humid Tropical:  Orchidacee, Rubiacee and Huphorbiacew comprising 
10-28 per cent. of the total species, and included in the first 3-10 Families. Dry 
Tropical Floras constitute a less uniform sub-type, and are regarded as derivative. 
2. North Temperate (incl. Arctic and Subantarctic): Ranwnculacee, Rosacee, 
Oruciferce, Cargophyllacee and Umbellifere forming 12-25 per cent., and in the first 
9-19 Families. 
