1012 SUMMARY OF CURRENT RESEARCHES RELATING TO 



tmtcd, the latter caused by rhythmical increases and decreases in the 

 energy of growth of aliquot portions of the receptacle. The imbricate 

 aestivation is quite distinct in its origin from the contorted., and. varies 

 greatly in its mode of development. 



Formation of Buds in Phanerogams.* — Prof. A. Famintzin 



contests the view hitherto held that so called, "axillary shoots" in 

 flowering plants may spring either from the internode above tho 

 subtending leaf or from the base of the leaf itself. Among Mono- 

 cotyledons he has examined the "axillary buds" in seedlings of 

 maize and in stems of Tradescantia zebrina ; and among Dicotyledons 

 in Ephedra, Casuarina, Syringa, Vopulus, 9nA.Auc.vha. In all these 

 cases he found the " axillary " buds to spring from the internode 

 above the subtending leaf. They are usually more or less oblique, but 

 sometimes horizontal, with the growing point towards the supporting 

 leaf, and the base facing the axis of the stem ; and corresponding in 

 all respects to the position of the buds in Mosses and Equiseiacese. 

 The formation of new tissue takes place much earlier in the subtend- 

 ing leaf than in the internode and bud above it. If these observations 

 represent a general law, there are not in flowering plants any axillary 

 buds in the correct sense of the term. 



Anatomy and Physiology of Stinging Hairs.j — Dr. G. Haber- 

 landt has examined the structure of the stinging hairs in a number of 

 plants. The main features show a great uniformity in the multi- 

 cellular base surmounted by the very large secreting cell. Below 

 the silicified apex of the latter the cell-wall is always very thin. In 

 Loasa papaverifolia the brittleness is occasioned by the deposition, 

 not of silica but of calcium carbonate, and in Jatropiha dimulam by 

 lignification. In other cases the lignified apex is partially or entirely 

 wanting. 



The substance which gives the stinging properties to the fluid 

 of the glands of the common stinging nettle is not, as has been 

 generally supposed, formic acid, which could not produce the effect 

 in such small quantities. Dr. Haberlandt also states that the irrita- 

 tion must be produced by a fixed substance, since the dried contents 

 of the gland will cause the ordinary effect of a nettle sting if intro- 

 duced beneath the skin. He finds always in the fluid a substance 

 which exhibits all the properties of an albuminoid. The substance 

 which produces the inflammation is probably a compound of the 

 nature of an unformed ferment. 



Tendrils of Cucurbitaceae4 — Dr. O. Midler has examined the 

 structure and the causes of twining in 38 species of Cucurbitacese, 

 and divides them into four classes, according to the degree of com- 

 plexity of the tendrils. Where the tendrils are compound, he regards 

 the basal portion as in all cases morphologically a stem, the branches 



* Mel. Biol. Bull. Acad. Imp. Sci. St. Pctersbourg, xii. (18S6). See Bot. 

 Centralbl., xxvii. (1886) p. 95. 



t SB. K. Abad. Wiss. Wien, xciii. (1886) pp. 123-45 (2 pis.). See Bot. 

 Centralbl., xxvii (1886) p. 7. 



J (John's Beitr. zur Biol. d. Bflanzen, iv. (1880) pp. 97-144 (3 pis. and 2 figs.). 



