Maryland and Virginia Medical Journal, Volume 15 (Google eBook)

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Page 206 - I believe that animals have descended from at most only four or five progenitors, and plants from an equal or lesser number. "Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype. Therefore, I
Page 192 - The affinities of all the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth. The green and budding twigs may represent existing species ; and those produced during each former year may represent the long succession of extinct species. At each period of growth all the
Page 192 - life. The limbs divided into great branches, and these into lesser and lesser branches, were themselves once, when the tree was small, budding twigs ; and this connection of the former and present buds by ramifying branches may well represent the classification of all extinct and living species in groups subordinate to groups. Of the many twigs
Page 192 - twigs have tried to branch out on all sides, and to overtop and kill the surrounding twigs and branches, in the same manner as species and groups of species have tried to overmaster other species in the great battle of life. The limbs divided into great branches, and
Page 205 - Although I am fully convinced of the truth of the views given in this volume under the form of an abstract, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts, all viewed from a point of view directly opposite
Page 129 - that there is no exception to the rule that every organic being naturally increases at so high a rate, that if not destroyed, the earth would soon be covered by the progeny of a single pair.
Page 130 - that the Fulmar petrel lays but one egg, yet it is believed to be the most numerous bird in the world. " One fly deposits hundreds of eggs, and another, like the hippobosca, a single one; but this difference does not determine how many individuals of the two
Page 196 - an action, which we ourselves should require experience to enable us to perform, when performed by an animal, more especially by a very young one, without any experience, and when performed by many individuals in the same way, without their knowing for what purpose it is
Page 197 - set to work, fed and saved the survivors ; made some cells and tended the larvae, and put all to rights. What can be more extraordinary than these well-ascertained facts? If we had not known of any other slave-making ant, it would have been hopeless to have speculated how so wonderful an instinct could have been perfected.
Page 202 - read Sir Charles Lyell's grand work on the Principles of Geology, which the future historian will recognize as having produced a revolution in natural science, yet does not admit how incomprehensibly vast have been the past periods of time, may at once close this

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