ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 325 



Structure of Psaronius * — A. Carpentier records the discovery of 

 the roots of Psaronius in the Lower Westphalian at Vicoigne in the 

 north of France ; the structure is preserved by silicification, and the 

 author gives an account of the microscopic details, calling special atten- 

 tion to the interradical conjunctive tissue. 



Development of Salvinia natans. f — S. Zawidzki writes on the 

 development of Salvinia natans. The stem has a two-sided apical cell, 

 the edge of which is perpendicular to the surface of the water. The 

 stem is divided into nodes and internodes. One-quarter of every segment 

 produces a node, and the remaining three-quarters forms the internode. 

 In the node every four peripheral cells form the initials for the two 

 aerial leaves, the submerged leaf and the branch. All these lateral 

 organs grow with a two-sided apical cell. The ventral halves of each 

 segment in the aerial leaves form new two-sided apical cells, from which 

 the lamina is formed. The vascular bundles of the lamina arise in 

 connexion with the segmentation. A similar relation to the segmentation 

 is seen in the formation of the intercellular spaces, stomata and hairs, 

 and especially of the hair-tufts on the upper side. The hairs have basal 

 growth and usually stand by an air space. All hairs, save those of the 

 superior hair-tufts, are brown-tipped. The sori are metamorphosed 

 apices of the submerged leaves, the tip of which forms new initials, 

 whence arises the iudusium. The indusium is not closed at apex. 

 Branching occurs very early in the submerged leaves ; each of the right 

 peripheral cells can produce a lateral bi-anch. The branch-initials extend 

 the length of a half -segment. The sori stand in spirals ; the oldest, and 

 sometimes the next, are macrosori ; the others are all microsori. 



Bryophyta. 



(By a. Gepp.) 



Gemmje of Hepatics.| — H. Buch writes on the gemmae (Brutorgane) 

 of the hepaticffi, dividing his subject into two parts : (1) morphology 

 and development ; (2) morphological significance. He follows the 

 nomenclature of Correns, and divides them into Brutblatter, Brutkelche, 

 Brutaste, Brutknospen, Brutkorper, Brutkorner. Part I. deals almost 

 entirely with Brutkorner, which are composed of from one to four cells, 

 and may arise endogenously or exogenously. The endogenous gemmte 

 of Haplozia caespiticia are described in detail. Exogenous Brutkorner 

 are only found on the leaves of acrogenous hepatics, and this type also 

 is described in detail. He writes also of the slime-papilla3 ; these are 

 absent in Kantia. Part II. treats of the manner of origin, whether 

 connected with regeneration or with the formation of adventive shoots. 



Radula epiphylla and its G-enimae.§— K. Goebel writes on the 

 gemmae of Radula epifphylla. These are peculiarly organized. The 

 plant is epiphytic on leaves, and the gemmae correspond well with 



* Comptes Rendus, cliv. (1912) pp. 671-3. 

 t Beih. Bot. Centralbl., xxviii. (1912) pp. 17-65 (89 figs.). 



J Ueber die Brutorgane der Lebermoose. Helsingfors : 1911 (4 pis.). See also 

 Bot. Centralbl., cxix. (1912) pp. .352-3. 

 § Flora, iv. (1912) pp. 157-64 (figs.). 



