50 



an accurate mapping of the surrounding neighbourhood, at the same time 

 supplying full particulars.* 4 



A discussion having taken place relating to the locality of the ancient 

 remains described by Mr. Conwell, it was — 



Resolved, — That it be recommended to the Council to make an ap- 

 plication to Government to have the hitherto undescribed monuments 

 near Oldcastle surveyed, measured, and mapped. 



The Rev. Samuel Haughton, M. D., Fellow of Trinity College, Dub- 

 lin, read the following paper : — 



Notes on Animal Mechanics. 



No. III. — On the Muscular Mechanism oe the Leo of the Osteich. 



On the occasion of the death of a fine male Ostrich, during the month 

 of January last, in the Zoological Gardens of this city, I secured the 

 body for dissection in Trinity College, and requested Mr. Macalister, of 

 the Royal College of Surgeons, to avail himself of the opportunity thus 

 afforded of completing the anatomical investigations he had previously 

 commenced in the Royal Dublin Society, by the dissection of a fe- 

 male Ostrich, in the summer of 1863. Mr. Macalister availed him- 

 self of the opportunity, and has laid before the Academy such results 

 of his dissections as seemed to him most worthy of record. My own 

 attention was directed especially to the investigation of the muscular 

 mechanism of the leg of the Ostrich, which I have long regarded as 

 one of the most interesting pieces of mechanism in the animal king- 

 dom, and I was fortunate enough to discover, in the digastric rectus fe- 

 moris muscle, what I believe to be the key to the explanation of the 

 complicated muscular apparatus of the Ostrich's leg. 



The leg of the Ostrich is to be regarded as a long rod bent at four 

 distinct points, which attains its greatest amount of shortening or bend- 

 ing at the moment the foot touches the ground, and which is suddenly 

 straightened or elongated by the simultaneous contraction of all the 

 muscles. The effect of the sudden elongation of the leg is, to throw 

 the whole body of the bird forward, as if from a catapult, from the 

 point of support of the foot ; and while the body of the animal is thus 

 projected through the air, the antagonist muscles that flex the several 

 joints come into play, and are assisted in their action by some very re- 

 markable contrivances in the heel joint, which I shall describe and 

 figure. 



It is necessary to the perfection of the mechanism, that the greatest 

 possible amount of muscular force shall be expended in straightening 

 or unbending the legs, alternately projecting the animal from foot to 

 foot along the ground, the leg being at its maximum of flexure at the 

 moment of touching the ground, and at its maximum of elongation at 



* The inferences in the above paper are to drawings preserved in the Library of the 

 Royal Irish Academy. — P2d. 



