The evolution of the skull and the cephalic muscles: a comparative study of their development and adult morphology. Part IV. The Theria, and index
Abstract
[No abstract is given, the work begins as follows] The Theria. The Superficial Facialis Musculature. The Stylohyoideus ;Muscle. The Posterior Digastric Muscle, The Mandibular Muscles. The Branchial and Hypobranchial Muscles. In Part I of this work, dealing with the fishes, instead of describing the muscles of each species before proceeding to those of the next, each was described for the whole of each group. The object was to focus attention upon muscle groups and entities, rather than the musculature of the fishes themselves. It appeared to the writer that the muscular systems of the vertebrata had been evolved, by adaptive modification, from some generalized fish type, and quite early it appeared that a deal of this adaptive modification might be observed in the conditions presented by the elasmobranchian cephalic musculature. Therefore, the first portion of this work was devoted to establishing muscle groups and muscle entities, and at the same time, to an inquiry as to whether the varying complexity of the arrangement and modification of these, essentially similar, groups and entities in the process of functional adaptation in conformity with or response to skeletal changes within the fishes shed any light on their origin from a more generalized condition. ... [etc.]
