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Página 155 - ... by elongated processes varying in number from one to six or seven. Each cell of the inner wall contains numerous red or brown granules, a few transparent globules, and a single large clear mesoblast. When decomposition ensued, these cells became still farther separated from each other and danced about in the manner which I have just described. The vibratile cilia were not observed to share in this movement ; in fact I could not detect their presence, because, no doubt, they had become decomposed...
Página 72 - The addition of burned clay to soils has also a secondary influence 5 it renders the soil porous, and, therefore, more permeable to air and moisture. The ammonia absorbed by the clay or ferruginous oxides is separated by every shower of rain, and conveyed in solution to the soil.
Página 439 - Buffalo-Grass,1 so abundant and so widely diffused over the broad, arid region which separates our Pacific from our Atlantic possessions, is one of the humblest plants of its order, rising only a few inches above the surface of the soil ; but at the same time it is one of the most important and useful, since it forms the principal subsistence of the buffalo for a part of the year, and no less so of the cattle of the emigrant. The botanical history of this little grass, now happily completed by Dr.
Página 128 - The Geology of Pennsylvania. A Government survey, with a general view of the Geology of the United States, Essays on the Coal Formation and its Fossils, and a description of the Coal Fields of North America and Great Britain.
Página 108 - I was struck with the similarity of these bead-like strings to the fibrillae of the muscle, and upon close comparison I found that the former were exactly of the same size, and had the same optical properties as the latter. Some of these appeared to be attached to the ends of the flat, ribbon-like fibres, and others at times loosened themselves and swam away. I was immediately impressed with the daring thought, that these Vibrios were the...
Página 382 - Dolomites, magnesites, and magnesian marls have had their origin in sediments of magnesian carbonate formed by the evaporation of solutions of bicarbonate of magnesia. These solutions have been produced either by the action of bicarbonate of lime upon solutions of sulphate of magnesia, in which case gypsum is a subsidiary product, or by...
Página 287 - The wreck of these ejecta was visible in the patches of 'ceneri impastati,3 containing fossil bones, below the mouth of the cavern. That a long period must have operated in the extinction of the hysena, cave-lion, and other fossil species is certain, but no index: remains for its measurement. The author would call the careful attention of cautious geologists to the inferences — that the...
Página 195 - Agassiz maintains, substantially, that each species originated where it now occurs, probably in as great a number of individuals occupying as large an area, and generally the same area, or the same discontinuous areas, as at the present time.
Página 147 - Sir Humphry Davy gave me the analysis to make as a first attempt in chemistry, at a time when my fear was greater than my confidence, and both far greater than my knowledge ; at a time also when I had no thought of ever writing an original paper on science. The addition of his own comments, and the publication of the paper, encouraged me to go on making, from time to time, other slight communications, some of which appear in this volume. Their transference from the Quarterly...
Página 424 - Hobson, RN, Captain Allen Young, and myself. As a somewhat detailed report of our proceedings will doubtless be interesting to their Lordships, it is herewith enclosed, together with a chart of our discoveries and explorations, and at the earliest opportunity I will present myself at the Admiralty to afford further information, and lay before their Lordships the record found at Port Victory. I have, &c., FL M'CLINTOCK, Captain, RN To the Secretary of the Admiralty, London.