ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 271 



Transformation of Albumen in Plants. * — According to 

 E. Schulze, experiments made on seedlings have led to the following 

 conclusion : that in the decomposition of albumen which accompanies 

 germination, a mixture is always produced of various nitrogenous 

 products of decomposition, and that these products are the same as 

 those formed on heating nitrogenous substances with acids or alkalies. 

 In seedlings of lupins were found, in addition to asparagin, a small 

 quantity of leucin and traces of tyrosin, as well as some apparently 

 new amido-acids, one of which, crystallizing in needles or plates, 

 showed the composition CgHnNOa- 



A second result obtained was that the nitrogenous products of the 

 decomposition of albumen formed in seedlings occur in totally different 

 proportionate quantities to those obtained by the heating of albuminous 

 substances with acids or alkalies. In seedlings of Leguminosae 

 asparagin, in those of Cucurbitaceae glutamin is the most abundant 

 albuminoid. 



Chlorophyll which does not assimilatcf — Hanstein has ob- 

 served in the central cells of Chara chlorophyll-bodies containing 

 starch which could not be regarded as the product of assimilation. 

 C. Dehnecke has now investigated a number of similar instances, in 

 which the starch contained within the chlorophyll-grains appears not 

 to serve the purpose of immediate assimilation, but to be stored up as 

 a reserve material. This occurs, for example, in the cortical paren- 

 chyma of Impatiens parviflora and of many Polygonaceae ; in the young 

 leaf-stalk of ferns, in the stem of the seedling of Iiaj)hanus niger, in 

 the young sepals of Tropceolum majus and Primula Auricula, in the 

 pericarp and flesh of the fruit, placenta, &c., of many plants, and in 

 green potatoes. That there is no actual difference between those 

 chlorophyll-grains which have and those which have not the function 

 of assimilation is shown by the fact that in many cases the same grain 

 will sometimes exercise successively the two functions of the storing 

 up of starch and of assimilation. In certain cases the chlorophyll- 

 grains of the kind under discussion were all found on the under 

 side of the organ, and this was proved by experiment to be the result 

 of gravitation. 



Influence of the Intensity of Light on the Chlorophyll in the 

 Assimilating Parenchyma. :|: — Professor Stahl points out the import- 

 ance, with regard to the reception of light, of the two different 

 characteristic forms of cells ordinarily found in the parenchyma of 

 flat leaves, the palisade-cells, with their longer diameter at right 

 angles to the surface of the leaf, and the spongy parenchyma, the cells 

 of which have their greatest extension parallel to the surface. In 

 horizontal leaves the palisade-cells are found on the uj)per surface, 

 the spongy parenchyma on the lower surface, while in vertical leaves 



* Landwiitlisch. Jahrb. v. Thiel, ix. (1880) p. 689. See Bot. Centralbl., i. 

 (1880) p. 1613. 



t Dehnecke, C, ' Ueber nicht assimilirencle Chlorophyllkorper,' Koln, 1880. 

 See Bot. Ztg., xxxviii. (1880) p. 795. 



X Bot. Ztg., xxxviii. (1880) pp. 868-74. 



u 2 



