| OCR Text |
Show 1896.] ON THE MYOLOGV OF RODENTS. 159 CONCLUSION. I do not feel justified in attempting to draw any general conclusions as to the relations of the various divergences from the common type that I have described; but I think that I have brought together enough matter to show that when a much larger number of facts has been collected, the method of investigation I have been following may furnish another clue to that riddle of zoology, the classification of birds. But in addition to this systematic interest, the comparative anatomy of a group of creatures so large in numbers and so alike in anatomical structure offers a field for the investigation of the innumerable divergences and convergences that have taken place in the evolution of the group. I cannot see that interpretations of isolated characters have any value. When we know the comparative anatomy of the greater number of characters that make up an animal, and not only those that seem to distinguish it as a speries, the time may come for interpretation. But to those who care for discussions concerning isolated characters, I may suggest the problem : in these loopings of the gut in birds, there is an almost kaleidoscopic variety, and apparently these varieties are of systematic value ; what are their utilities ? 4. Myology of Rodents.-Part II. An Account of the Myology of the Myomorpha, together with a Comparison of the Muscles of the various Suborders of Rodents. By F. G. PARSONS, F.R.C.S., F.Z.S., F.L.S., Lecturer on Comparative Anatomy at St. Thomas's Hospital. [Keceived December 14, 1895.] The present paper is intended to be a second instalment to one " On the Myology of the Sciuromorphine and Hystricomor-phine Eodents," which 1 had the honour of reading before this Society in 1894 (see P. Z. S. 1894, p. 251). I am again indebted to the kindness of the Society's Prosector, Mr. F. E. Beddard, for a large proportion of my material; indeed, it was his suggestion that a detailed examination of the muscles of Rodents would be of practical value in the Dissecting-Boom at the Gardens that determined me to undertake the work in the first instance. The first part of this paper contains an account of the muscles of thirteen Myomorphine Eodents. and as a statement of actual facts will, I hope, prove of some value. The second part is devoted to a series of summaries and generalizations founded upon the facts with which these and previous dissections have furnished me. This part I regard as of less value than the first, because future dissections may make many alterations necessary. It seems well, however, to take stock of the mass of material from time to time as it accumulates. |
