Download or read book Reports of the President and the Treasurer written by Vassar College and published by . This book was released on 1926 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vassar Quarterly written by and published by . This book was released on 1917 with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulletin of the American Museum of Natural History written by American Museum of Natural History and published by . This book was released on 1963 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprises articles on geology, paleontology, mammalogy, ornithology, entomology, and anthropology.

Download or read book Report of the Assistant Director and of the Curators of the U S National Museum written by United States National Museum and published by . This book was released on 1924 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report on the Progress and Condition of the U S National Museum for the Year Ending June 30 written by United States National Museum and published by . This book was released on 1921 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Catalog of the Library of the American Museum of Natural History 59 2 59 57 5 written by American Museum of Natural History. Library and published by . This book was released on 1978 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report Upon the Condition and Progress of the U S National Museum During the Year Ending June 30 written by United States National Museum and published by . This book was released on 1924 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanisms of Sound Production in the Ariid Catfishes Galeichthys and Bagre written by William N. Tavolga and published by . This book was released on 1962 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The skeletal basis of the sound producing mechanism in the ariid catfishes Galeichthys felis and Bagre marinus consists of a thin shelf of bone which is firmly attached to the anterior dorsal wall of the swim bladder. This so-called 'elastic spring,' or 'Springfederapparat,' is formed from the parapophysis of the fourth vertebra. The anterior ramus of this parapophysis, herein named the 'Müllerian ramus' (after Johannes Müller who, in 1842, first described the structure), is the main vibrating element in sound production. The skulls and anterior vertebral complexes of Galeichthys and Bagre are figured and described, with comparisons with a non-sonic silurid form, Wallago. The 'protractor muscle' (so named by Bridge and Haddon in 1893) which activates the Müllerian ramus is a highly vascularized conical muscle, the origin of which is on the under side of the epiotic lamina and insertion on the Müllerian ramus. It is innervated by the dorsal branch of the occipital nerve. The relationship of this nerve to the cranial nerves of higher vertebrates is controversial, but it is probably homologous with the hypoglossal (XII). Stimulation of the protractor muscle or its nerve supply with repetitive spike-form potentials results in an audible sound output from the Springfederapparat. This response can be recorded and analyzed, and its fundamental pitch is equivalent to the pulse frequency of the stimulus. The protractor muscle is remarkable in that it can withstand stimulations of 300 or more pulses per second without going into immediate tetany. In Bagre, the frequency response of the sonic system is about an octave higher than that in Galeichthys. Spontaneous sounds from these species consist of low-pitched grunts (fundamental pitch of about 150 cycles per second) and, in Bagre, higher, sob-like sounds (400 cycles per second or over). The harmonic components of both artificially induced and spontaneous sounds can be influenced by the amount of sound reflectance in the external environment. Even under partially anechoic conditions, the sound output is virtually a pure tone. Damage to the swim bladder reduces the amplitude of the sound but not its timbre (i.e., harmonic content). It was concluded that the swim bladder does not serve as a resonating chamber for these sounds, nor is it a true amplifier. Rather, it transfers the energy from the small area of the vibrating Müllerian ramus to the larger area of its entire outer surface, thus making the propagation of the sound from its source to the water more efficient. In acoustical and electronic terms, the swim bladder is an impedance matching device"--P. 27.

Download or read book Catalog written by Library of the Marine Biological Laboratory and the Woods Hole Oceanographic Institution and published by . This book was released on 1971 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reef Creature Identification written by Paul Humann and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1992, this guide has been significantly expanded in a new 3rd edition. The popular, user-friendly field guide, covering all major groups of marine invertebrates encountered by divers on coral reefs and adjacent habitats, has grown to include 900 species beautifully documented with more than 1200 underwater photographs -- nearly doubling the total in the previous editions. Les Wilk has joined Paul Humann and Ned DeLoach authoring the comprehensive new edition.

Download or read book Detecting Ecological Impacts written by Russell J. Schmitt and published by Academic Press. This book was released on 1996-01-17 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detecting Ecological Impacts: Concepts and Applications in Coastal Habitats focuses on crucial aspects of detecting local and regional impacts that result from human activities. Detection and characterization of ecological impacts require scientific approaches that can reliably separate the effects of a specific anthropogenic activity from those of other processes. This fundamental goal is both technically and operationally challenging. Detecting Ecological Impacts is devoted to the conceptual and technical underpinnings that allow for reliable estimates of ecological effects caused by human activities. An international team of scientists focuses on the development and application of scientific tools appropriate for estimating the magnitude and spatial extent of ecological impacts. The contributors also evaluate our current ability to forecast impacts. Some of the scientific, legal, and administrative constraints that impede these critical tasks also are highlighted. Coastal marine habitats are emphasized, but the lessons and insights have general application to all ecological systems.

Download or read book American Seashells written by Robert Tucker Abbott and published by Van Nostrand Reinhold Company. This book was released on 1974 with total page 1214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides information on the physical characteristics, geographical locations, and bathymetric ranges of sixty-five hundred species of North American mollusks.