OK THE MYOLOGY OF AJSTOMALTJEUS. 317 



The Position of Anomalurus as indicated by its Myology. 

 By E. Gr. Parsons, F.E.C.S., F.L.S., Lecturer on Comparative 

 Anatomy at St. Thomas's Hospital and Hunteriau Professor 

 at the Eoyal College of Surgeons. 



[Read 4th May, 1899.] 



Fob several years I have been ansious to dissect the muscular 

 system of Anomalurus, and to compare it with that of other 

 rodents ; I am therefore especially grateful to Professor Howes for 

 kindly placing at my disposal a young specimen which originally 

 came from the Congo. Personally I hold that muscles, if judi- 

 ciously used, are ca,pable of giving a great deal of information 

 about the relationship of animals, because they do not readily 

 adapt themselves to changed conditions of life. This opinion is 

 the result of a systematic survey of the muscles of several orders 

 of mammals, a survey which has occupied me for several years ; 

 and although, in the opinion of many anatomists, muscles are 

 very unstable structures, I would submit that both in Dobson's 

 hands, and to a lesser degree in my own, a certain amount of 

 definite assistance has been afibrded systematists by them in 

 classifying animals whose position had previously been doubtful. 

 Anomalurus gives a very good opportunity for testing the 

 resources of myology, since its position is so uncertain. A study 

 of Oldfield Thomas's paper " On the Grenera of Rodents"* will show 

 how many different positions have been assigned this animal, and 

 one can therefore enter upon the task of finding out what its 

 muscles have to tell with a perfectly free and unbiassed mind. 



It may be asked why I have elected to prefer the muscles to 

 any of the other systems of the body as an index of relationship. 

 It is chiefly a matter of convenience for comparison. The 

 nervous, vascular, or alimentary systems may well have many 

 secrets to tell, but in order to understand them it is necessary 

 that the details of these parts in a large and representative series 

 of other rodents should be recorded and collated. This work 

 I have already done for the muscles f, and I am therefore able 

 to describe these structures in Anomalurus more briefly than I 

 should otherwise feel justified in doing, premising that those 

 muscles which are not mentioned are fairly stable in all rodents 

 and, in my opinion, of little or no value for classificatory 

 purposes. 



* P. Z. S. 1896, pp. 1012-1028. t P. Z. S. 1894, p. 251, & 1896, p. 159. 



IINN. JOUEN. — ZOOLOGY, YOL. XXVII. 24 



