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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



and the ratio of length to breadth in 1000 terminal leaflets and 1000 

 lateral leaflets of three different plants of Laburnum. His results 

 being of some interest, he tested his conclusions with measurements of 

 these three factors upon nineteen others, and from the same plant in 

 different years. He finds evidence of heterophylly in Cytisus Labur- 

 num. There is a strong positive correlation between the length and 

 breadth of the leaflet. Longer leaflets are relatively smaller than 

 shorter ones. The terminal leaflets are longer than the lateral ones, 

 but narrower. The difference in length is more pronounced the longer 

 the end leaflet may be, and the difference in breadth less pronounced 

 in cases of very broad side leaflets. 



All these characters differ in different years, so that though two 

 stocks may diverge widely, they need not bring about genotypic dif- 

 ference. No varieties based on these characters can be distinguished, 

 as there are transitions without marked gaps. The length of the 

 terminal leaflet seems to depend on habitat. Specially sunny habitats 

 produce longer leaflets. He finds no support for the Eitter Ludwig 

 theory, as no special maxima on Fibonacci figures or their derivatives 

 could be discovered. — G. F. S. E. 



Leguminosae, Style and Stigma in. By 0. Monch {Beih. 

 Bot. Cent. Bd. 27, Abt. i. Heft 1, pp. 83-126; with 12 figs.).— De- 

 scribes and figures the style and stigma in the chief tribes of this order. 

 These show great variety and may be characteristic of species and 

 genera, but not of higher groups. The stigma is (in Papilionaceae and 

 several Caesalpiniae) easily rubbed off and disorganized, changing into 

 lumps of some oily material. This enables the pollen grain to reach 

 the cell-sap of the stigmatic tissue. Many self-sterile Leguminosae can 

 be self-pollinated when the stigma is rubbed. Similar stigmas occur 

 in Orassulaceae, Poly gala, Corydalis, Atropa, and Rhododendron, but 

 not in Mimosaceae, Eosaceae, and Saxifragaceae, i 



The oily matter makes (in these last-named forms) the stigmatic 

 surface sticky so that the pollen grains are held on to the stigmatic 

 surface.— G. F. S. E. 



Lens-cells in the Epidermis of Mesembryanthemum pseudo- 

 truneatellum. By F. Summers {Ann. Bot. xxv. pp. 1137-45; 

 Oct. 1911). — This peculiar species from the Cape belongs to the section 

 Sphaeroidea, where two similarly shaped leaves roughly sphaeroidal in 

 form compose practically the whole aerial part of the plant. The 

 plants resemble the stones of the Karroo amongst which they grow. 

 The structure is described in detail, and it is shown that well- 

 developed lens-cells are present, but they do not function as organs o] 

 perception for the direction of the incident light rays, neither have 

 they any connexion with heliotropic phenomena. They are stated te 

 be quite efficient in structure, but their function is almost wholly shu 

 out by the encrustation of calcium oxalate found in the epidermis 

 As the plant in its native habitat is subject to strong solar illumination 

 the encrustation is a protection when this becomes too strong. 



