ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 73 



In the secondary phloem new latieiferous elements are continually 

 beiug formed by the cambium. The members of one group branch and 

 anastomose freely among themselves, but do not anastomose with the 

 members of other groups. The cortical tubes form a continuous reticu- 

 late cylinder all round the stem. It is probable that at the nodes all 

 the latieiferous systems stand in radial connection with one another. 

 By treating sections of the stem with ether, and staining with hsema- 

 toxylin, numerous nuclei were seen in the latieiferous vessels, both of 

 the phloem and pith ; and a protoplasmic layer could also be detected 

 lining the vessels, showing that they retain their living contents after 

 maturity. 



In Eevea brasiliensis, Miss Agnes Calvert also succeeded in detecting 

 all three systems of latieiferous tissues in older seedlings. In this 

 plant, although the latieiferous tubes consist mainly of vessels formed 

 by the fusion of rows of cells, yet, like the latieiferous cells of other 

 euphorbiaceous plants, they retain the power of independent growth, and 

 may put out branches which grow by their apices. The nuclei are 

 particularly distinct in the latieiferous tubes of all three systems, and 

 may be seen even without staining. They frequently contain very 

 distinct nucleoli. 



Tubular Cells of the Fumariacese.* — Herr E. Heinricher objects 

 to Zopf's description f of the idioblasts in the tissue of Fumariaceaa as 

 " tannin-receptacles." The contents of these cells consist of a mixture 

 of various substances, and the author prefers for them the designation 

 " tubular cells " (Schlauchzellen), which gives no indication of their 

 contents. The characteristic and universal constituent of their contents 

 is a fatty oil, with which may be associated protoplasm, a pigment or 

 its chromogen, various salts, and tannin. Usually tannin is altogether 

 wanting, and, if present, is only in minute traces. Anthocyan may 

 occur, but is not generally present. The cells which contain anthocyan 

 are generally independent idioblasts, similar to those found in other 

 forms, and quite distinct from the characteristic tubular cells of the 

 Fumariacese. 



For the demonstration of these cells the author uses potassium 

 biniodide, or an alcoholic or aqueous solution of iodine, by which their 

 contents are coloured yellow-brown or dark-brown, the oil and proto- 

 plasm as well as the tannin. If an alcoholic solution is used, the 

 brown colour soon disappears, owing to the great solubility of the oil 

 in alcohol. The author considers the best reagent for tannin to be 

 the neutral salts of iron ; potassium bichromate may also be used. 



Super-endodermal Network in the Root of the Caprifoliaceae.J — 

 M. P. van Tieghem continues to give the result of his researches on 

 the super-endodermal network, as found in the root of various plants. 

 In the present paper this structure is described as it occurs in the 

 various genera of Caprifoliaceae. In Viburnum Tinus and V. Opulus, for 

 example, all the super-endodermal cells of the young root are strongly 

 thickened and lignified on their radial and transverse faces. These 

 thickenings are coloured bright red by fuchsin. Here and there a cell 

 of the antepenultimate layer also bears thickening bands. Several 



* Ber. Deutsch. Bot. Gesell., v. (1SS7) pp. 233-8. 



t See this Journal, 1887, p. 427. 



X Bull. Soc. Bot France, xsxiv. (1S87) pp. 251-3. Of. this Journal, 1887, p. 986. 



