ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 223 



ture, a solution of copper sulphate and lime in water. Other copper 

 compounds are also found effective, and F. Clark, Cornell University, 

 has made a large series of experiments with fungus spores to test their 

 effects on fungus development. He grew the spores on a decoction of 

 sugar-beet, that being found most suitable for comparative tests. Copper 

 salts dissolved in pure water were more toxic in their effect than in any 

 other medium. The addition of potassium sulphate or chloride caused 

 a reduction in toxic properties. An arnmoniacal solution of copper car- 

 bonate was more deadly in its effects than copper sulphate, but as in the 

 open field the ammonia exaporates quickly it is found to be less efficient 

 than Bordeaux mixture. The author deduced from his experiments, as 

 already suggested by Swingle, that the spores themselves have a solvent 

 action on the copper and thus bring about their own destruction. Almost 

 all vegetable decoctions have the power of dissolving copper. If a too 

 concentrated solution of copper is used for spraying peach trees, the 

 leaves of which have a delicate cuticle, the epidermal cells dissolve 

 enough copper to seriously injure the plant. One value of the lime 

 ingredients in the Bordeaux mixture is the retarding action that it 

 exercises on the solution of the copper by the ammonia, and by the 

 nitrites and nitrates of the atmosphere ; it is thus rendered effective 

 as a fungicide over a more prolonged period of time. 



Protophyta. 

 Schizopliyceae. 



G-omontiella, a new Genus of SchizophyceaB.* — In bogs in Kou- 

 mania E. G. Teodoresco finds a new form, in which the edges of the 

 elongated frond are brought nearly close together, forming a nearly 

 closed cylinder, with only a narrow longitudinal fissure. The following 

 is the diagnosis of the new genus Gomontiella : — Trichomata libera, 

 simplicia, longitudinaliter in canaliculum cylindricum v. modice planum 

 convoluta ; vaginas firmse, pertenues : cellulae omnes conformes a vertice 

 (in sectione transversa) visae profunde semilunataB v. in annulum con- 

 tortae, apices versus sensim paululuinque attenuatae ; cellula apicalis 

 calyptram non praebens. Propagatio divisione transversali filamen- 

 torum. 



Schizomycetes. 



Bacterial Disease of the Potato. | — G. Delacroix now claims the 

 microbe which causes the wide-spread diseise of the potato already 

 described, as a new species, and names it Bacillus solanicola. It also 

 attacks the tomato, but not so virulently. 



Beggiatoa. J — G. Hinze has investigated the structure of the re- 

 markably large cells (the largest among Schizomycetes) of Beggiatoa 

 mirabilis. He finds the protoplasmic contents to consist of a parietal 

 layer, and of thick bands which separate the vacuoles from one another. 

 There is no sharply differentiated central body or nucleus. The 

 strongly refringent granules of sulphur occur both in the parietal layer 



* Verhaudl. k. k. Zool.-bot. Ges. Wien, li. (1901) pp. 757-60 (1 pi.). 



t Comptes Rendus, cxxxiii. (1901) pp. 1030-2. Cf. this Journal, 1901, p. 689. 



X Ber. Deutsch. Bot. Ges., xix. (1901) pp. 369-74 (1 pi.). 



