310 Morphologie und Teratologie. — Physiologie. 



closed by the normal whorl In Cerastiiim qiiaternellum FenzL, 

 and C. glomeratum Thuilicr ovules vvere found containing two 

 distinct nucelli, each vvith a fully developed embryo-sac. 



M. Wilson (Glasgow). 



GiBSON, R. J. Harvey, The axillar y scales oi aquatic 

 Monocotyledons. (Journal of the Linnean Society. Vol. 

 XXXVII. No. 259. 1905. p. 228—237. With plates 5 

 and 6.) 



The author describes the axillary scales occurring in many 

 oi the Helohlae giving an account of their position and struc- 

 ture in twelve genera. The scales vary considerably in number 

 in the different species, 1 — 27 occurring in each axil. They are 

 almost simultaneous in development with the leaves^ arising 

 from a multicellular ridge and the mode of growth is invariably 

 basal. The cells are deeply stainable, containing abundant 

 protoplasm and nuclei. In many cases the basal cells of the 

 scales become cutinised and the cell contents disappear. 



These scales are considered to be homologous with the 

 more specialised and solitary ligules of Isoetes, Lepldodendron 

 and Selaginella ; they resemble the latter in their chief charac- 

 teristics but differ in the non-differentiation of a special glosso- 

 podium and in the non-development of any vascular düatation 

 of the leaf trace below the point of origin. These differences 

 may be caused by the aquatic habit. The scales in such a 

 type as Halophila can only bear analogy to the stipules com- 

 mon in the Dlcotyledons. M. Wilson (Glasgow). 



ViLMORiN, Ph. L. DE, S u r 1 e s t u b e r c u 1 e s a e r i e n s de 1 a 

 Pomme de terre. (Bull. Soc. bot. de Fr. 1905. p. 535 



—537.) 



On sait que des tubercules aeriens apparaissent parfois 

 sur la partie inferieure des tiges de la Pomme de terre, a 

 Taisselle des feuilles, lorsque la Vegetation est exuberante. La 

 Variete „Geante bleue" du Solanum tuberosum^ a presente ä 

 Verrieres des tubercules aeriens sur des'rameaux nes dans une 

 inflorescence, probablcment ä la place de certaines fleurs; ces 

 rameaux avaient un diametre superieur ä celui de la tige support 

 de l'inflorescence. Les tubercules aeriens portaicnt de petites 

 feuilles laterales ou terminales et deux d'entre eux s'etaient 

 ramifie's. C. Queva (Dijon). 



Gerlach und Vogel, Ammoniakstickstoff als Pflanzen- 

 nährstoff. Mit 2 Fig. (Centralbl. f. Bakt. Abt. II. Band 

 XIV. 1905. p. 124—128) 



Nach neueren Feststellungen scheint auch der Ammoniak- 

 stickstoff von unseren Culturpflanzen aufgenommen zu werden, 

 ohne dass also vorheriger Uebergang in Salpeter erforderlich: 



