372 ANNUAL RECOKD OF SCIENCE AND INDUSTRY. 



pure oxygen, at ordinary atmospheric pressure, failed to pass 

 beyond the first stages of germination. When, however, the 

 oxygen was diluted with four fifths of its volume of hydro- 

 gen, and likewise when its tension was decreased by the air- 

 pump to about one fifth of the ordinary atmospheric pressure, 

 the seeds germinated as well as in ordinary air. These ob- 

 servations are quite in accord with others lately made by 

 Bert upon the influence of variations in atmospheric pressure 

 upon the vital phenomena of plants. The experiments of 

 Bert showed that the germination of seeds in ordinary air 

 was hindered when the pressure was increased to five atmos- 

 pheres, and that it failed entirely in an atmosphere of pure 

 oxygen at ordinary pressure; and, finally, that in ordinary 

 air, at a low pressure (a nineteenth to a seventh of one at- 

 mosphere), the germination was likewise hindered. Too large 

 a quantity, or too high a tension, of oxygen in the atmos- 

 phere seems to be unfavorable to germination of seeds. Jour. 

 Linnwau Soc, XIY. 



DE. HOOKER ON CAEXIVOEOUS PLANTS. 



Dr. J. D. Hooker's recent address to the Department of 

 Zoology and Botany of the British Association had for its 

 subject the carnivorous habits of plants " our brother or- 

 ganisms." After a brief history of what has been learned of 

 the insect-devouring habits of the Dioncea of the Carolinas, 

 the Sarracenia of the Atlantic States, and the Darlingtonia 

 of California, and of the more widely distributed species of 

 Drosera, he adds the results of his own observations of the 

 numerous tropical pitcher-plants {Nepenthes) of the East In- 

 dian Archipelago. The pitcher is not here a transformed 

 leaf or leaf-blade, as in the other instances, but an appendage 

 developed at the tip of the midrim of the leaf, corresponding 

 to the simple water-secreting gland which occurs at the same 

 point in several other plants. The rim of the pitcher and 

 under surface of the lid are more highly colored than the rest 

 of the plant, and are provided in almost every species with 

 numerous honey-secreting glands, below which is a surface 

 covered with a glass-like cuticle, affording no foot-hold to in- 

 sects. The rest of the pitcher is entirely occupied with a 

 secreting surface, crowded with spherical glands in immense 

 numbers. The fluid contained in the cavity is collected be- 



