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IRotea^ 



I^^VVO kinds of corpuscles are stated to occur in the bacterial 

 cell, one lying just inside the cell-wall and staining deeply 

 with phenol-fuchsin solution ; whilst the second is analo- 

 gous to the nuclei of the higher vegetable cells. When unstained, 

 the nuclei of the bacteria are said to resemble vacuoles. 



— Centr. f. Bakt. u. Parasit. Agric, vi., 384. 



Structure of the Bacteria. — Zettnow has published a paper 

 in which he showed that the chromatin portion, usually seen when 

 bacteria are stained by the ordinary methods, is the nucleus with 

 its sheath. The plasma can only be seen when the specimen is 

 treated with mordants. Leoffler's method was adopted in the 

 experiments, and the preparations were afterwards photographed. 

 Spirillimi repens, Proteus vulgaris, Chromaium okeni, and the cork- 

 screw bacillus were thus dealt with, and the plasma and nucleus 

 were readily seen. 



Protection of Plants against Larv.e. — A. Laboulbene pro- 

 poses to protect beetroot and cruciferous garden plants against the 

 attacks of larvae by the employment of decoctions of plants con- 

 taining powerful alkaloids. Unlike mineral poisons — such as 

 Scheele's green — the alkaloids lose their poisonous properties by 

 undergoing oxidation upon the plants or in the soil, so that after 

 performing the required work no risk of ulterior mischief need be 

 anticipated in adopting this method. Repeated experiments have 

 been made with decoctions of the stems and leaves of Delphinium 

 grandijiorum, as well as with the seeds of the same plant, and of 

 D. Ajoecis. It is thought, however, that the seeds of D. staphis- 

 agria may be more energetic in their action, and the aconites, 

 stramonium, belladonna, hyoscyainus, etc., are suggested as afford- 

 ing suitable material for experimenting in this direction. — Compt. 

 Rend., cxvi., 702. 



Fertilisation of Orchids. — J. H. A. Hincks, in discussing the 

 fertilisation of orchids without pollen, quotes Professor Henslow, 

 who shows how a microscopical examination of the structure of 

 the essential organs at once renders apparent the reason of so 

 small an amount of good seed being set. The pollen, instead of 

 being in well-formed distinct grains, is arrested in development, 

 andj while the grains are still in contact, a common extine clothes 

 the whole of each mass. Development does not proceed until the 

 pollen-mass has been placed upon the stigma. In the pistil, 

 degeneracy is indicated by the prevailing parietal placentation and 



