348 SUMMARY OF CURRENT RESEARCHES RELATING TO 



which stand as sentinels at the hase of the pedicel throughout the day, 

 and ward off other insects, arachnids, and the larvae of Lepidoptera, 

 which would otherwise attack the young leaves. The anthocyan serves 

 as a protection against too strong solar radiation. The simple non- 

 glandular hairs are coated with a waxy suhstance which protects the 

 young leaves against the injurious action of dew and frost. 



Extra-nuptial Nectaries of Prunus Laurocerasus.* — Sig. L. Mac- 

 chiati describes in detail the red or brown patches at the base of the 

 young leaves of the cherry-laurel, in which is secreted a nectariferous 

 fluid. He regards it as incontestable that this bright colour attracts 

 ants and other Hymenoptera which would be injurious to the plant. 

 When growing in very shady places these spots are destitute of colour, 

 but still produce the nectariferous secretion. In mature leaves they have 

 disappeared altogether. 



Anatomy and Morphology of Rhus vernicifera.f — Pi of. M. Mbbius 

 contributes an exhaustive account of the anatomy and morphology of the 

 Japanese lacquer-tree. Among the very numerous details the following 

 may be especially mentioned. The formation of thyllse in the secreting 

 canals altogether resembles that which occurs in the Simarubeae, but 

 which has not hitherto been observed in the Anacardiaceae. The species 

 is strictly dioecious, no intermingling of male and female flowers having 

 been observed. The wax exuded from the mesocarp forms a thick in- 

 crustation on the inner side of the cell-walls. Its purpose appears to 

 be the attraction of birds, especially pigeons, which feed on the mesocarp 

 and pass the seeds without digesting them. The seeds contain a thin 

 layer of endosperm within the thin testa. 



Outgrowths on Hibiscus vitifolius.l — Miss E. Dale has studied the 

 outgrowths which occur commonly on the green parts of this plant, and 

 concludes that they are of a pathological character, and are produced by 

 the direct influence of external conditions, chiefly light and moisture. 

 The intumescence consists exclusively either of the epiderm alone or of 

 the epiderm and the cells lying immediately below it. 



Intumescences of Eucalyptus and Acacia. § — Herr P. Sorauer has 

 investigated the nature of these structures found on several species of 

 the genera named, which frequently have a moss-like appearance at the 

 apex. They appear to be the result of a depressed assimilation due to 

 a deficiency of light. A high temperature, together with an abundant 

 supply of water, then causes an irritation which can be responded to 

 only by elongation of the cells at the expense of the cell-contents already 

 contained in them. 



* Histology of the Root-tubercles of the Leguminosae. || — After a 

 copious synopsis of the results obtained by, and the views of previous 

 observers, accompanied by a very complete bibliography, Dr. E. Paratore 

 gives an account of his own observations on the microscopic structure 

 and the contents of the tubercles on the roots of several species of 



* Bull. Soc. Bot. Ital., 1899, pp. 144-7. 



t Abbaudl. Senckenberg Naturf. GeSell., xx.(1899) pp. 201-47 (I pi. and 29 figs.). 



% Proc. Cambridge Phil. Sua, x. (1900) pp. 192-209 (3 pis.). 



<j Ber. Deutscb. Bot. Gesell., xvii. (1899) pp. 456-60 (1 fig.). 



(I Malpighia, xiii. (1899) pp. 211-36 (1 pi.). 



