ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 70 



insoluble on treatment with alcohol and corrosive sublimate, the 

 author considers it probable that the " gum-cells " do not contain 

 albuminoids, but drops of oil imbedded in a protoplasmic network, 

 and proposes for them the preferable term " oil-cells " (Fettzellen). 



Nucleus in Amylaceous Wood-cells.* — B. Schorler has inves- 

 tigated the structure of the nucleus in the starch-containing cells of 

 a large number of trees and shrubs belonging to different natural 

 orders. He finds a nucleus universally present in living cells, 

 although of so delicate a nature that it is often not visible except by- 

 hardening and staining. Its form is originally spherical or ellipsoidal ; 

 but external forces subsequently bring about a great variety of changes. 

 The size also varies very greatly ; it is on the average larger in 

 Coniferse than in dicotyledons. The measurements are given of the 

 nuclei in a great number of species, the length varying from 3 to 

 25 '5 fx; the breadth from 1-5 to 13*5 /x; while some are nearly as 

 broad as long, in others the length is ten times the breadth. The 

 internal differences are but comparatively small, as shown by the 

 different degrees in which pigments are taken up. One or more 

 nucleoli may be present, and a nuclear membrane can usually be 

 detected. 



Even in mature wood-cells the nuclei are often not only in a living 

 condition, but are even capable of division. The nucleus may remain 

 unchanged so long as starch is still stored up in the cells. In the 

 older rings of wood they may even retain their vitality for a period of 

 eighty-six years [Sorhus tormindlis), or even longer. When dead the 

 nucleus does not necessarily disappear, it may become disorganized 

 by a complete change in its internal structure, exhibited by its losing 

 its granular character and becoming rigid, frequently in consequence 

 of becoming permeated by resin. Such nuclei, of a dark brown 

 colour, have been found in the 110th annual ring of the yew. 



Peculiar Stomata in Coniferae.f — K. Wilhelm describes a peculiar 

 structure of the stomata in the leaves of Abies jpectinata, the outermost 

 cavity of the stoma containing, at all times of the year, a number of 

 nearly black patches composed of a great quantity of minute granules. 

 The particles are nearly insoluble in cold, but very soluble in hot 

 alcohol, and are of the nature of wax, apparently identical with that 

 which covers the surface of the leaves. Their purpose is apparently 

 to hinder transpiration. This peculiar substance appears to be 

 invariably present in the stomata of Abies pectinata, and in many 

 other Abietinese and Cupressineae, but was not found in the yew. 



Root-liairs.l — F. Schwarz publishes an exhaustive account of the 

 root-hairs of plants in their morphological and physiological relations. 

 Although it is possible in certain cases for roots to absorb nourish- 

 ment from the soil when destitute of root-hairs, yet the latter are 

 unquestionably the most important organs for this purpose. The 



* Jenaisch. Zeitschr. f. Naturw., xvi. (1883) pp. 329-57. 

 t Ber. Deutsch. Bot. Gesell., i. (1883) pp. 325-30. 



X Unters. Bot. Inst. Tubingen, i. (1883) pp. 135-88 (I pi.). See Bat. 

 Centialbl., xv. (1883) p. 337. 



