TRANSACTIONS OF SECTION K. 691 
The whole cone is very small and weakly constructed. 
It is found to be hermaphrodite, the microspores being at the top, where the 
cone is smaller in diameter than in the lower macro-sporangiate region, 
The macro- and micro-sporangia and their sporophylls have the same structure, 
In each case the radial extension of the sporophyll is very slight; the sporangium 
is attached to the middle of the horizontal portion by a narrow circular neck of 
tissue. 
Between this attachment and the upturned lamina is a large ligule. The base 
of this is surrounded by transfusion tissue of the ordinary type. 
The macrospores occur four in each sporangium, and are characterised by bear- 
ing long branched spines, 
The micro-sporangia when isolated have been often confused with those of 
Miadesmia. 
They are shown to belong to this Bothrodendron cone by comparison with 
attached examples and with detached macro-sporangia, with which they agree 
perfectly in structure. 
4, On the Hairiness of certain Marsh Plants. 
By Professor R. H. Yaprpr, IA. 
In contrast to true aquatics, a large number of marsh plants possess more or 
less abundant hairs on their leaves and other parts. In some cases the hairs are 
sparse; in others (e.g., Spirea ulmaria) the hairs form a dense felt on the under- 
surfaces of the leaves. But in the leaves of many species there are marked 
seasonal differences in this and other respects. Thus in Mentha aquatica, 
Lysimachia vulgaris, Epilobium hirsutum, Spirea ulmaria, and other species, the 
first-formed leaves of the year are small and glabrous, while the later-formed 
leaves are larger and more hairy. Asa general rule the low-growing shoots have 
either glabrous or only slightly hairy leaves, while the taller, erect shoots are 
more hairy. 
Spirea wlmaria is especially striking in this respect. It forms in the spring- 
time successively glabrous, partially hairy, and hairy leaves, the pubescence on 
the latter being exceedingly dense, particularly in the case of the leaves on the 
erect flowering stems. The distribution of the hairs on the partially hairy leaves 
is interesting, and seems to follow quite definite rules. Thus (1) in a partially 
hairy leaf the terminal leaflet is always the most hairy, the pubescence on the 
other leaflets decreasing from above downwards; while (2) in a partially hairy 
leaflet the pubescence first appears round the edges of the leaflet, or sometimes in 
well-marked bands between the main veins. 
Now, there exists an entirely glabrous form of Spirea ulmaria, the so-called 
var. denudata, which, so far as my own experience goes, occurs in Nature only in 
quite sheltered places. On growing this variety in situations exposed to strong 
winds it appears to suffer more from the exposure than the ordinary hairy form, 
The effect of such exposure is that the leaves soon become partially withered, the 
distribution of the withered parts very nearly coinciding with the distribution of 
hairs on a partially hairy leaf of the ordinary variety; that is to say, the most 
vulnerable parts of the leaves are precisely those parts on which hairs first appear 
in a partially hairy leaf. 
5. On the Inheritance of certain Characters in Primula sinensis. 
By R. P. Greaory, IA. 
The primary object of these experiments, begun in 1903 by Mr. Bateson and 
the writer, upon Primula sinensis and other heterostyled plants, was the investi- 
gation of the inheritance of the characters of long and short style. Ina previous. 
communication’ we showed that the inheritance of these characters is Mendelian, 
1 Brit. Assoc. Rep., 1905; Roy. Soc, Proc., B, vol. lxxvi., 1905. 
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