374 Physiologie. 



ments des feuilles de quelques Legumineuses. 

 (Bull. Sect. sc. Acad. Roum. I. p. 225—232. 1913.) 



Les auteurs ont etudie particulierement la nature et l'arrange- 

 ment des tissus dans les organes moteurs des Legumineuses : Mimosa 

 pudica, Acacia lophantha, Phaseolus multißorus et Acacia Julibrissin. 

 Ils donnent les conclusions suivantes: II n'est pas necessaire pour 

 qu'une courbure se produise que le protoplasma soit plus irritable 

 dans certaines portions du renflement; il suffit qu'il y soit en plus 

 grande quantite et que des raisons anatomiques rendent inegales les 

 variations de turgescence. II y a un rapport constant entre la Posi- 

 tion du maximum du tissu cortical et la direction des mouvements. 

 La transmission de l'irritation s'effectue probablement par des tibrilles 

 protoplasmiques unissant les cellules. La nature du tissu meduUaire, 

 le degre de concentration des faisceaux et la nature du tissu perili- 

 berien des renflements jouent incontestablement un grand röle dans 

 l'amplitude des mouvements. L'amplitude moyenne des mouvements 

 a ete pour Mimosa pudica de 6,9 mm, Phas. mult. de 4 mm, Acac. 

 loph. de 2,9 mm, Acac. Jul. de 1,4 mm. Plus la fusion des faisceaux 

 est grande (comme de Miyn. pud.) plus la moelle est reduite et le 

 diaraetre total restant egal sur toute la longueur du renflement plus 

 le tissu cortical est developpe. Le tissu medullaire tend ä amoindrir 

 les mouvements, tandis que l'ecorce les amplifie. Pour les details 

 anatomiques voir l'original, M. J. Sirks (Haarlem). 



Kelley, W. P., The effect of manganese on pineapple 

 piants and the ripening ofthe pineapple fruit. (Hawaii 

 Agr. Exp. Sta. Bul. XXVIII. p. 1—20. pl. 1-2. 1912.) 



Roots of pineapple piants are very sensitive to soil conditions- 

 When grown in manganese-containing soils the roots are injured- 

 being swollen at the tips, and producing few if any lateral roots. 



The stem of the plant contains large amounts of starch which 

 is the source of the sugar in the ripened fruit, the green fruits 

 themselves containing only very little starch. Pineapples gathered 

 while green do not develop a normal sugar content in subsequent 

 ripening, since they are cut off from the supply of reserve starch 

 in the stem. 



The most conspicuous effect of manganese on the pineapple 

 plant is seen in the bleaching of the leaves due to disintegration 

 of the Chlorophyll and plastids. 



The ash of piants grown on manganiferous soils has an abnor- 

 mally high calcium content, while the magnesium and phosphoric 

 acid content is low. G. L. Forster (St. Louis). 



Kelley, W. P., The function and distribution of manga- 

 nese in piants. (Hawaii Agr. Exp. Sta. Bul. XXVI. p. 1—21. 1912.) 



Various piants grown on manganese-containing soils are affected 

 differently; some are stunted and killed back with yellowing of the 

 leaves, while others appear to be unaffected. In a number of piants 

 the Chlorophyll is decomposed and the chloroplasts may be disinte- 

 grated. This does not appear to be at all correlated, with excessive 

 oxidative activity. 



Ash analyses of piants grown on manganese-containing soils 

 show that considerable manganese is absorbed, and in connection 

 with this there is a disturbance of the calcium-magnesium ratio. 



