500 Transactions of the Society. 



glaucum, and Xanthorhiza apiifolia. Edgeworth says the latter has 

 two forms of pollen, one as above and the other ellipsoid. He also 

 shows the pollen of Anemone curonaria with seven facets round the 

 base. 



The prevailing colour of the pollen is often of a rich golden hue 

 and glossy, but that of Anemone coronaria is purple, while that of 



A. nemorosa is yellow. 



The diffei'ent species of Clematis differ a good deal from one 

 another. C. vitalba is of the ordinary ellipsoid form, but coarsely 

 granular, while C. paniculata is only finely so. C. rnontana rubens 

 has very short pollen, while C. Jackmanni is faceted, as already 

 mentioned. 



The pollen of Tlialictrum is at first viscid, but soon becomes 

 dry, and is scattered by the wind as well as carried by bees. 



The surface of the stigma generally consists of domed, often 

 oily cells, which in many cases {Clematis vitalba, and C. Jack- 

 manni for instance) gradually elongate into papillae. 



Thalictrum is partly anemophilous, the stamens are long and 

 slender, and the pollen rapidly dries, so that it is easily carried by 

 the wind. In T. Jiavum it is very light and floats freely in the 

 air. The stigma in Thalictrum is often winged and papillose. 



Berberidej*;. — The common or ellipsoid type of pollen occurs 

 frequently if not predominantly in this family. It is recorded in 

 Epimedium alpinum, E. rubrum, Nandina, domesfica, Podophyllum, 

 Bouyardia Ranwolfii, Holbocllia latifolia, Decaisnea insignis, and 

 Jeffersonia binata. 



The pollen of Berberis vulgaris is spherical, with three and occa- 

 sionally four shallow furrows meeting in the centre. B. Darwinii, 



B. aquifolium, B. repens, B. nepalensis, B. Wallichiana, B. japonica, 

 and B. buxifolia, have very similar pollen. 



The furrows oi B. Wallichiana are especially deep. The hybrid 

 B. stenophylla is similar, but sometimes has eight furrows. 



The pollen of B. asiatica is, on the contrary, according to Edg- 

 worth, a disk with six facets. 



The surface of the pollen also shows various differences. That 

 of Epimedium is striated, of Bougardia is granular, of Diphylleia 

 cyiiiosa is echinate. 



Nymph.eace^.. — N. alba and N. tuberoses belong to the comraon 

 type, but the pollen is densely spiny, while in IV. stellata and N. 

 tetragona it is smooth. Nuphar luteum. has specially long and 

 strong spines, the furrows are absent and the end view is round. 

 JVelumbium speciosum has elevated blunt points, and sometimes 

 four furrows. 



N. gigantea minor, N. lotus, N. dentata, and iV". stellata have 

 orbicular flattened pollen, made up of two unequal divisions. 



The pollen of Victoria regia is a tetrad, and the individual grains 

 are triangular, turgid, and with obtuse angles. The two pairs are 

 at right angles. 



