764 8UMMA.RY OF CtTRRENT RESEARCHES RELATING TO 



organ, so that its apex is its oldest part, and tlio ono whicli first passes 

 over into its perinaucut condition. 



Propagula of Pinguicula.* — M. M. Hovclacqtic describes organs of 

 propagation hitherto unknown in Pinguicula vulgaris, in the form of buds 

 or propaguha seated in the axil of the lower leaves of the underground 

 stem, which ultimately become detached. Each bud consists of a short 

 axis and four or five leaves. The first internode elongates considerably. 

 The axis of the bud contains at its base only two vascular bundles ; higher 

 up they unite, but not so completely but that the two bundles can still 

 be distinguished. The planes of insertion of the roots do not form at the 

 periphery of the vascular cord a layer resembling that which clothes tho 

 vascular system of tho underground stem. Nothing warrants the hypo- 

 thesis that the axis of the propagulum is a stem with several confluent 

 central cylinders. 



Flower of Orchideae.j — Herr E. Pfitzer commences a series of papers 

 dealing with the details in the structure and development of the flowers 

 of Orchidcfe. The jjresent instalment deals with the Cypripedilinse 

 (^Ciipripcdilum, Selenipedilum, Paphiopedilwui), Opbrydinae (Orchis Morio), 

 and Neottiina3 (Epipactis, Cephalantliera^. 



Ovules of Rumex.J — From examination of the structure of anomalous 

 flowers of Rumex scuiatus, Dr. S. Calloui draws conclusions favourable to 

 the hypothesis of Sachs, that the ovule of Bumex is an axial structure, 

 and not a production of the carpel. In the anomalous flowers examined 

 it has become modified in a way opposite to that of the ovary. It is the 

 result of a vertical and lateral prolification of the axis, and becomes 

 changed into a floral organ, i. e. into a pistil. The mode of evolution of 

 the ovule leads to the same conclusion. 



Seeds of Pharbitis triloba.§ — M. K. Hyrano describes in detail the 

 structure of this plant, a native of Japan, and especially of the seeds, 

 from which he obtains a resin identical in composition and in medicinal 

 properties with the convolvulin contained in jalap-root ; and suggests 

 that the seeds of the Japanese plant may be introduced into commerce 

 as a purgative. A resin was obtained by dissolving the finely powdered 

 seeds in alcohol, precipitating with acetate of lead, and purifying the 

 filtrate. The resin thus obtained consisted partly of an oil, the 

 remainder being nearly pure convolvulin. 



Structure of Impatiens.]] — Dr. E. Heinricher describes several pecu- 

 liarities of structure in different species of Impatiens examined by him. 

 Alone among Dicotyledons, with the exception of Cucurhita, and in all 

 the species examined, he finds in the embryo four secondary roots formed 

 already in the seed, which develope rapidly on germination and serve to 

 fix the young plant in the soil. 



In J. Balsamina {Balsamiua hortensis), capensis, and other species, 

 the cells of the embryo, and esjjccially those of the cotyledons, display 

 strong thickenings of their walls ; these thickenings serving as reserve 

 food-materials, which are dissolved and used up in germination. The 

 micro-chemical reactions of these thickenings are given in detail, and 



* Comptes Rendus, cvi. (1888) pp. 507-10. 



t Pringsheim's Jahrb. f. Wiss. Bot., xix. (1888) pp. 155-77 (2 pis.). 



X Mem. Soc. Phj's. Geneve, xxix. (1887) 23 pp. and 3 pis. 



§ MT. Med. Faculfat K. Japanischen Universitat, i. (1888) pp. 201-8 (2 pie.). 



II Flora, Ixxi. (1888) pp. 163-75, 179-85 (1 pi.). 



