ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 197 



Dr. S. Prowasck * also describes the formation of both the 2-armed 

 and the 4-amied glands of Utricularia vulgaris. The i-armed glands 

 possess the property of absorbing ammonium carbonate and nitrate, as 

 well as the products of decaying animal substances ; the bacteria which 

 occur in the bladder play but an unimportant part in digestion. 



Green Hemi-Parasites.f — H. Heinricher now gives, in considerably 

 greater detail, his observations on the germination and development of 

 Bartsia (Bartschia in op.) alpina, and Tozzia alpina, both belonging to 

 the Rhinantheae. 



In Bartsia alpina haustoria make their appearance on the root in a 

 very early stage of germination. This fact, and the entire absence of 

 root-hairs, seem to prove that parasitism is absolutely essential for this 

 species ; and this was confirmed by the constant failure to keep autono- 

 mous plants alive for more than a few months. It appears to have no 

 exclusive host; the haustoria will attach themselves to roots of both 

 Monocotyledons and Dicotyledons ; like, however, most Rhinantheaa, 

 especially Euphrasia and Alectorolophus, this species has retained its 

 power of assimilation. The parallel is further drawn between Bartsia 

 and Lathrsea, and especially between B. alpina and L. clandestina. 



The seed-vessel of Tozzia is not a capsule, but a nucule. The seeds 

 contain a very small embryo. Unlike all other green Rhinantheae, the 

 cotyledons are developed underground. Again, Tozzia resembles Oro- 

 banclie and Lathrsea, and differs from all other Rhinantheae, in requiring 

 the chemical irritation of the root of the host-plant for the full germi- 

 nation of its seeds. Tozzia alpina may blossom the second year after 

 germination, while Bartsia alpina requires four or five years. After 

 once blossoming, the plant perishes. Artificially, Tozzia was cultivated 

 on Alchemilla vulgaris, Bumex alpinus, and Banunculus lanuginosus ; 

 doubtfully on a grass, and on Medicago lupulina. During by far the 

 greater part of its life it is holoparasitic ; its hemi-parasitic life lasts 

 •nly for a few weeks. Its power of assimilating is much less than that 

 of other green Rhinantheae. 



Some further anatomical details respecting Tozzia are given, and the 

 probable genetic connection of the Rhinantheae and Lathreae with one 

 another and with non-parasitic forms is discussed. 



Formation of New Stems from Old Willows. J — Dr. G. Fischler 

 describes the process of rejuvenescence of portions of the stem which 

 occasionally occurs in old willows. When the heart-wood has perished we 

 frequently find strips of the splint-wood also dying throughout the 

 whole length from root to crown. Between these dead strips there 

 remain strips of living splint-wood with sound bark. By the activity 

 of the cambium on the living strip a callus is formed which gradually 

 grows round and separates the living from the dead wood, and may ulti- 

 mately form a new stem distinct from the old. Figures of sections of 

 Salix alba are given in illustration of the process, with a photograph of 

 an old tree with a dead main stem and a quite distinct and vigorous 

 regenerated young stem. 



* Verhandl. k. k. Zool.-bot. Ges. Wien, li. (1901) pp. 648-51 (11 figs.). 

 t Prmgsheim's Jahrb. f. wiss. Bot., xxxvi. (1901) pp. 665-762 (2 pis. and 7 tigs.). 

 Cf. this Journal, 1900, p. 607. J Flora, xc. (1902) pp. 273-S. 



