ZOOLOGY AND BOTANY, MICBOSCOPY, ETC. 607 



Raphides in Typha.* — Dr. M. Kronfeld finds crystals of calcium oxalate 

 in several species of Typha. They were found only in the male flowers, 

 in the filament and connective, and especially in the endothecium or inner 

 layer of the wall of the anther. In the female flowers they appear to be 

 replaced by a yellow oily substance. 



Calcium oxalate in the Cell-wall of Nyctaginese.f — Herr A. Heimerl 

 finds the presence or absence of a deposit of calcium oxalate in the cell -wall 

 in difi'erent genera of this order to go along with other characters of 

 taxonomic value. It occurs in the form of minute granules of irregular form, 

 chiefly in the outer and inner walls of the epidermal cells of the stem and 

 of both surfaces of the leaf, less often in the lateral walls of the same cells. 



Presence of a Glucoside in the alcoholic extract of certain plants.]: 

 — M. E. de Wildeman has found in the alcoholic extract of certain plants 

 a substance which will reduce Fehling's solution. The reaction was well 

 marked with an extract obtained from the leaves of the ivy ; also with one 

 obtained from the common Pelargonium. In the latter case tannin was also 

 present, which was precipitated as a blue-black sediment by salts of iron. 

 The author also prepared alcoholic extracts of certain algae : — Ulothrix 

 zonata, Ulva Lactuca, and Nostoc commune. In each case Fehling's solution 

 was reduced. The glucoside present in each of the above has not yet been 

 isolated. 



Localization and Significance of Alkaloids in Plants. § — MM. L. 

 Errera, Ch. Maistriau, and G. Clautriau state that in the majority of cases 

 the alkaloids are found in the interior of the cells, dissolved sometimes in 

 the cell-sap, occasionally in mucilaginous matter. 



Alkaloids are distinctly local in their occurrence in the plant. They 

 occur in active tissues such as the growing point or the embryo, or around 

 the fibro-vascular bundles, or in the epidermis, or finally they may occur, 

 as in Papaver, in the laticiferous vessels. 



Physiologically, they may be considered as the waste products of the 

 activity of the protoplasm. 



Alkaloids are formed essentially in the active tissues, where they are 

 decomposed and transformed into albuminoids. From the interior the 

 alkaloids are transported towards the periphery in order that they may 

 be more easily oxidized and to serve as a protection to the plant. When 

 special secretions occur they are used as reservoirs to store the alkaloids. 



(3) Secretions. 



Caoutchouc in Plants. || — Dr. Kassner has determined the amount of 

 caoutchouc in the latex of several native (German) plants. In Souchus 

 oleraceus, the mean of several experiments gave a percentage of 0*18 per 

 cent. This was accompanied by an unusual proportion of proteinaceous 

 substances (15 '62 per cent.) and of potash (52-17 per cent, of the ash). 

 In Lactuca virosa he found the proportion of caoutchouc in the fresh latex 

 to be as high as 5 per cent. In Chelidonium majus and Eupliorhia Latht/ris 

 only slight traces of caoutchouc were found in the latex. The latex of 

 Asclepias Cornuti was also found to contain a considerable quantity of the 

 same substance, but was not examined at the time of the year when the 

 amount was likely to be the largest. 



* Bot. Centralbl., xxx. (1887) pp. 154-6. 

 t SB. K. Akad. Wiss. Wien, xciii. (1886) pp. 231-46 (1 pi.). 

 X CK. Soc. K. Bot. Bc4gique, 1887, p. 34. 



§ Errera, L., Maiatriau, Ch., and Clautriau, G., ' Prem. Eech. sur la localisation et 

 la signification des alcaloides dans les plantes.' Bruxelles, 1887, 29 pp. and 1 pi. 

 11 JB. Schles. Gesell. vaterl. Cultur, Ixiii. (1886) pp. 128-32, 181-6. 



