ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 655 



Herr M. Westermaier,* commenting on Kraus's conclusion*', points 

 out that, according to his own observations, tannin does in some cases 

 serve as a reserve-material for the building-up of new tissues, as in that 

 of the formation of roots on the branches of Salix. 



Formation of Calcium oxalate in plants.f — Herr F. G. Kohl con- 

 tends that lime can enter into soluble combinations with the carbo- 

 hydrates in the tissues of plants, and that it is in the form of these 

 compounds that the transference of lime takes place from one part of the 

 plant to another. He has obtained a compound of this kind of grape- 

 sugar and lime in both the solid and the dissolved condition. The 

 organs, therefore, where starch and other carbohydrates are stored up — 

 rhizomes, tubers, bulbs, seeds, bast-fibres, &c. — are also those where the 

 separation of calcium oxalate takes place. Moreover, all organs where 

 albuminoids are being formed have a decided acid reaction from the 

 presence of oxalic acid. This is readily proved in the case of growing 

 points. If light is excluded, calcium oxalate is formed only in small 

 quantities, or not at all. 



Influence of Light on the formation of Calcium oxalate.^ — Herr 

 N. A. Monteverde has demonstrated, by experiments on Papilionaceas, 

 that the intensity of light has a very powerful influence on the amount 

 of crystals of calcium oxalate formed in the stem and leaves. 



Production of Honey in Convallaria.§ — Herr S. Almquist describes 

 the mode of production of the honey in the flowers ( f ConvnUaria 

 Poli/goiiafiun and multifiora, viz. not from any j)it at the ba«c of the 

 perianth-tube, but from the primary veins of the perianth, esiiecially of 

 tbe sepals. This may probably be tlie original type from which are 

 derived all tlie various modes* of secretion found in the Liliiflorae, viz. 

 from the central nerve of the petals {Lilium, Fritillaria, Gagea, &c.), 

 from folds between the carjoels {Allium, Ornithogalum, HyacintJius), and 

 from the tissue of tbe spur (some Orchideae). 



(3) Structure of Tissues. 

 Foliar Vascular Bundles. |1 — M. A. Prunet has made a close exami- 

 nation of the changes which the vascular bundles undergo in j)assing 

 from the stem to the leaves, chiefly in Dicotyledons. Tlie vessels 

 diminish in size, usually becoming more numerou«, and have thinner 

 walls ; the large secondary vessels disapj)ear, while the jwimary vessels 

 increase in number. I'he supporting elements of the bundle - the fibres 

 and the lignified parenchyme — disappear, and, when the bundle has 

 reached the base of the leaf, the vessels, usually arranged in rows p'aced 

 in a fan-like manner, are accompanied by parenchyme formed of cells 

 which are usually elongated, and have very thin walls. As a rule the 

 largest vessels are near tlie base of the bundles, thence diminishing 

 gradually towards the periphery, rapidly towards tlie base. The inter- 

 calary parenchyme between the bundles is remarkable from its richness 



* BcT. Deutsch. Bot. Gesell., vii. (ISSg^) pp. 98-102. 



t Bot. Centralbl., xxxviii. (1889) pp. 471-5. Cf. this Journal, 1888, p. 445. 



X Arb. St Petersburg. Naturf. Gesell., xviii. pp. 46-7. See Bot. Centralbl., 

 xxxviii. (1889) p. 48G. 



§ Bot. Sixllsk. Stockholm, March 21, 1888. See Bot. Centralbl., xxxviii. (1889) 

 p. 663. 



11 Comptes Rendus, cviii. (1889) pp. 867-9. 



