ZOOLOaY AND BOTANY, MICEOSCOPY, ETC. 91 



used up in germination : — Phaseolus multiflorus and vulgaris, Pisum 

 sativum, Ervum lens and ervilia, Medicago saliva, Soja hispisa, Ricinus 

 africanus, Cucurhita Pepo, Gucumis sativus, Brassica oleracea, Cannabis 

 saliva, Helianlhiis annns, and Zea Mays. 



2. Tlie presence of lime is not absolutely necessary : — Brassica 

 napus oleifera, Sinapis alba, Papaver sonmiferum, Carum Carui. It is 

 very advantageous in Polygonum Fagopyrum and Linum usitatissimum. 



3. All nutrient substances are advantageous for the development 

 of seedlings : — Polygonum Fagopyrum, Brassica oleracea and napus 

 oleifera, Sinapis alba, Micinus africanus, Cucurbita Pepo, Papaver 

 somniferum, Helianthus annuus, Carum Carui, and Zea Mays. 



4. Nutrient substances promote the development of seedlings, 

 even when lime is wanting, for a short time : — Polygonum Fagopyrum 

 and Zea Mays. 



5. One or two nutrient substances besides lime are required by 

 the germinating seed for the consumption of the reserve-materials : — 

 Medicago saliva. The researches did not positively determine whether 

 lime is necessary for the formation of the skeleton of the cell- wall, 

 or whether its only function is the transformation of starch into 

 cellulose. 



Structure and Function of Epidermal Tissue.* — M, Westermaier 

 has investigated the structure and function of the epidermal tissue 

 of plants from an anatomico-physiological point of view. Three 

 functions are especially traceable to the peculiarities of the structure 

 of this tissue : — 1. The watery contents of the epidermal cells and the 

 thinness of their radial walls point to a function in connection with the 

 interchange of fluid among the cells of the epidermis itself. They 

 constitute, in fact, a system for the storing up of water. 2. The 

 second function relates to the interchange of fluids between the 

 epidermal and the assimilating systems. 3. The epidermal system 

 serves as an envelope or protection for the more delicate tissues 

 beneath. A number of illustrations are given, in which each of these 

 functions of the epidermis is well illustrated. 



Influence of diiferent conditions on the Epidermis of Leaves.t 

 — In confirmation of his previous observations on the influence of 

 abundant nutrition on the formation of stomata and of hairs,| E. Mer 

 finds that the galls produced by insects on vine-leaves possess stomata, 

 even when found on the upper side of the leaves, while, under normal 

 conditions, stomata occur on the under side of the leaf only. The 

 galls on the leaf- stalk of Populus pyramidalis have a thick- walled 

 epidermis with a few stomata, though these are entirely wanting on 

 the thin-walled epidermis of the uninjured part of the leaf-stalk. 

 In Salix, on the other hand, the reverse is the case, stomata being 

 present on the uninjured parts of the leaf, but not on the galls. 

 Insolation has a marked influence on the form of the epidermal cells 

 and on the formation of stomata, increasing the number of the latter, 



* SB. K. Preuss. Akad. Wiss. Berlin, xxxvii. (1882) pp. 837-43 (1 pi.), 

 t Comptes Eendus, xcv. (1882) p. 395. 

 X See this Journal, ii. (1882) p. 530. 



