Download or read book The Osteology and Myology of the Pelvic and Pectoral Girdles and Appendages of the Mammalian Genus Ondatra muskrat with Comparative Notes on Neotoma wood Rat written by Francis Richard Flaim and published by . This book was released on 1956 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation attempts to provide a detailed morphological description of the bones and muscles of the pectoral and pelvic girdles and appendages of the muskrat and to compare them with the corresponding structures in the wood rate. Its value lies in elucidating a large number of structural details which, unfortunately, do not lend themselves readily to effective summarization. The following are some of the findings which, it is hoped, retain some degree of meaningfulness even when taken out of the more extensive descriptions of which they form a part. 1. The ischium and publis of the muskrat are longer in proportion to the entire length of the innominate bone than are those of the wood rat. The ilium of the muskrat, however, is relatively smaller with reference to its innominate than is the case in the wood rat. 2. The fossae of the tibia and tibula are relatively much longer in the muskrat than in the wood rat. 3. The fusion of the distal part of the tibia and fibula is complete in the muskrat, but it is incomplete in the wood rat. 4. The lateral superfiscal muscles of the pelvic girdle and appendages of the muskrat are proportionately larger and better developed that those of the wood rat. 5. A muscle which is anatomically analogous to the M. sartorius of other animals is present and readily discernible in the muskrat. 6. The M. semitendinosus of the muskrat is the most important flexor of the shank and also the most complicated muscle as regards its position, relations, and attachments. 7. The three heads of the M. gastrocnemius lateralis are much more distinct in the muskrat than in the wood rat. Since the wood rat is a cursorial animal, the muscles of the posterior appendages produce varied movements of the limbs in several different planes. In addition, the muscles must act individually as well as in antagonistic groups in order to accomplish the requisite refinements of these movements. The muskrat, however, is primarily a swimmer, and its adaptation to that type of locomotion is probably responsible, in larage measure, for the persistence in that animal of the following structural modification's: 1. The pes of the muskrat is relatively longer than that of the wood rate. This finding is consistent with other observations which have shown that the pes becomes relatively longer with increased specialization of its functions. 2. The tail of the muskrat is proportionately longer and thicker in cross section than that of the wood rate. In the former, it is used principally as a rudder to guide the animal through the water. 3. The shortening of the forelimbs and head in comparison to those of the wood rat's is another adaptive specialization. 4. In the muskrat the superior tuberosity of the ischium differs from a typical tuberosity such as that of the wood rat, in that it is a crest, which extends from the dorsocaudal angle of the ischium cranially for a distance equal to almost half the length of that bone. Its size and form reflect the relatively great development of the M. bicepts femoris in this animal. 5. The sacroiliac joint in the muskrat involves not only the firs sacral vertebra, but occasionally, also, the anterior part of the second. 6. The pelvic arch of the muskrat is "U" shape, whereas that of the wood rat is "V" shaped. In the muskrat, the innomiate bones are more extensively united along the ichiopublic symphysis and thus form a stronger and more rigid girdle than that of the wood rat. This sturdier girdle is required to support the heavier and more muscular appendages of the muskrat. 7. The third trochanter is present on the femur of both animals, but is much larger and more distal in position in the muskrat. In the latter species, it provides adequate attachment for the strong lateral superficial muscle group. 8. The M. biceps femora of the muskrat is relatively much larger than that of the wood rat. 9. The M. tenuissimus is regularly present in the wood rat, but is found only rarely in the muskrat. This is probably due to the great development of the M. biceps femoris in the latter form. 10. The writer agrees with Hill and Rinker in their identificaiton of the M. adductor magnusand M. adductor brevis. In brief, a detailed comparison of the bones and muscle of the pectoral and pelvic girdles of these two phylogenetically closely related mammals reveals numerous, and sometimes rather striking, specializations which can be attributed to the requirements of the very different habitats which they have come to occupy.
Download or read book Dissertation Abstracts written by and published by . This book was released on 1956-10 with total page 1050 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstracts of dissertations and monographs in microform.
Download or read book Transactions of the Illinois State Academy of Science written by Illinois State Academy of Science and published by . This book was released on 1964 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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Download or read book National Union Catalog written by and published by . This book was released on 1970 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes entries for maps and atlases.
Download or read book The Energetics and Biomechanics of Swimming in the Muskrat Ondatra Zibethicus with Hydrodynamic Considerations written by Frank E. Fish and published by . This book was released on 1980 with total page 294 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 82 59 9 9 written by American Museum of Natural History. Library and published by . This book was released on 1978 with total page 922 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 written by American Museum of Natural History. Library and published by . This book was released on 1977 with total page 754 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 11 6 59 1 written by American Museum of Natural History. Library and published by . This book was released on 1978 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1973 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bibliography of Wildlife Theses written by Julie L. Moore and published by . This book was released on 1970 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Dissertation Index 1861 1972 Biological sciences anatomy physiology and genetics written by Xerox University Microfilms and published by . This book was released on 1973 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Commencement written by Stanford University and published by . This book was released on 1954 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin of the Society of Vector Ecologists written by Society of Vector Ecologists and published by . This book was released on 1974 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1955 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to American Doctoral Dissertations written by and published by . This book was released on 1955 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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