34 NATURAL HISTORY SOCIETY OF DUBLIN. 



The following were declared duly elected as Ordinary Members : — 

 The Rev. J. Grainger, A. M., and Walter Smith, Esq. 



Pursuant to notice given at last General meeting by Dr. E. Perceval 

 "Wright, it was 



Resolved, — That in Section II., Rule 9, the word " three" be 

 substituted for the word " seven," in the second line. 



The meeting was then adjourned to the 5th of April. 



THURSDAY, APEIL 5, 1866. 

 David Moore, Ph.D., E.L. S., President, in the Chair. 

 A following paper was read : — 



Observations on Certain Muscular Peculiarities in some Monkeys. 

 By Alexander Macalister, M. D., L. R. C. S. I., F. R. G. S. I., De- 

 monstrator of Anatomy, Royal College of Surgeons, Ireland. 



In the structural peculiarities of each class of animals we are able to 

 detect certain prominent distinctive features which individualize that 

 class, and which separate it from those groups which are most closely 

 allied to it ; and of the sum of these we make up class, generic, and spe- 

 cific characters. All parts of the animal structure in some degree par- 

 ticipate in this generic and specific individuality ; and so we come to 

 recognise various types of brain, bone, and viscera, as connected with 

 each other, and with certain groups of external forms. These remarks 

 will be found to be applicable, in a particular sense, with regard to 

 the muscular system of animals ; and, although that branch of zoology 

 has been as yet comparatively nnwrought in a systematic point of 

 view, yet we know enough of the subject to enable us to recognise 

 the leading types of muscular arrangement as characteristics of the dif- 

 ferent groups of which the animal kingdom is made up ; all referrible, 

 as in the parallel case of the osseous system, to a definite hypothetical 

 radicle, or type animal. "We are thus very familiar with those muscular 

 peculiarities which constitute the human type, such as the differentiated 

 flexors and opponentes of the thumbs, the single insertion of the ex- 

 tensor indicis, and the great development of erectores spina?, glutseus 

 externus (properly named, in man, maximus), and of the gastrocnemial 

 series of muscles. We are equally familiar with the arrangement which 

 exists in the ordinary Quadrumana, Carnivora, Rodentia, or Ruminantia. 

 Of each of these types there are several lesser modifications, or sub-types, 

 equally interesting, as in them we frequently find the links which con- 

 nect the larger groups of forms with each other. 



In one of the above mentioned groups, the Quadrumanous or Simian, 

 there are some peculiarities which have not been particularly noticed 

 as yet, or which at least have escaped reference in the majority of the 

 books, and to a few of these sub-typical variations I would at present 

 wish to direct attention. 



