ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 265 



pigment, seen in the pink pigment of roses, pinks, and peonies. It is 

 soluble in water and alcohol, and can be obtained by evaporation in 

 the solid form. The alcoholic solution is nearly colourless, but is 

 turned red by a drop of hydrochloric acid ; ammonia and alkaline 

 carbonates turn it green, caustic alkalies yellow ; acids restore the red 

 colour. Its spectrum is characterized by a broad absorption band 

 between D and F. The scarlet colour of such flowers as the poppy 

 is the result of the presence of yellow grains of lipochrome in 

 addition to the red cell-sap ; and all intermediate shades are caused 

 by the relative proportion of these substances. The red colours of 

 fruits are due to similar causes. 



The blue and violet pigments appear not to be independent, but 

 derivatives of the red. When extracted by alcohol, a drop of acid 

 produces a red colour. The frequent change of colour in flowers from 

 red to violet, as in many Borragine^e, is probably due to acid salts in 

 the sap. 



The general conclusion is that while all other vegetable pigments 

 are closely related to one another, chlorophyll-green is a substance sui 

 generis. 



Red Pigment of Phanerogams.* — H. Pick replies to Wortmann's 

 objections brought against his argument j that the red colouring matter 

 of plants has frequently the object of materially assisting the transport 

 of starch in the plant. 



Mechanical Function of Crystals of Calcium Oxalate. J — 

 P. Baccarini suggests that the sclerenchymatous thickening of cell- 

 walls and the deposition of large quantities of crystals of calcium 

 oxalate, such as occurs in Viola, Colletia, Bhipsalis, Eryngium, &c., 

 are alternative processes, both intended to answer the same purpose 

 of furnishing a mechanical strengthening to the tissue, and that, con- 

 sequently, the two phenomena are very rarely found accompanying 

 one another. Especially does the deposition of masses of crystals in 

 the receptacle and ovary, particularly in the Epsaceae and Compositse, 

 form a kind of false tissue. 



Starch-meal. § — A. Tschirch points out the necessity of separating 

 the leading forms or types of starch-grains from the secondary forms ; 

 it is only from the former that any accurate judgment can be formed. 

 He gives, as an example, the difference between the typical forms of 

 the grains in bean- and pea-meal. The typical for the bean is elongated 

 and bean-shaped, triangular, oval, with large longitudinal fissure and 

 evident lamination. For the pea the type is roundish with cushion- 

 like projections, indistinct lamination, and more often radial striation. 

 The fissure is altogether wanting or very feebly developed. Secondary 



* Bot. Ztg., xlii. (1884) pp. 841-3. 



t See this Journal, iv. (1884) p. 257. 



X Ann. 1st. Bot. Roma, i. (1884) 8 pp. (1 pi.). See Oester. Bot. Zeitschr., 

 xxxix. (1884) p. 446. 



§ Vers. Deutsch. Naturf. u. Aerzte Magdeburg, Sept. 23, 1884. See Bot. 

 Centralbl., xx. (1884) p. 122. 



