NATURAL SCIENCES OF PHILADELPHIA. 469 



border, thus tending to tilt the right ventricle toward the left. (2) 

 The greater weight of the posterior aspect of the heart which throws 

 the posterior wall downward, and the anterior wall upward. ( 3) The 

 fixation of the left side of the heart, by the pulmonary veins, 

 directly in the median line, while the flattened sternum compels 

 the apex to lie either to one or the other side of the median line. 

 Dr. A. in conclusion divided the characteristics of man into two 

 groups. The first and most important being those the result of 

 evolving from a quadrupedal type a bipedal specialized form ; the 

 second, being those belonging to the disposition of special organs, 

 such as the teeth. Within this category may be placed the rudi- 

 ments of structure, which are better developed in quadrupeds, 

 and which often constitute the "varieties" of human anatomy. 



December 14. 

 The President, Dr. Ruschenberger, in the chair. 

 Twenty-nine members present. 



December 21. 

 The President, Dr. Ruschenberger, in the chair. 

 Twenty-five members present. 



December 28. 

 The President, Dr. Ruschenberger, in the chair. 

 Fifty members present. 



Win, Stevenson, Jos. R. Roach, H. C. Humphrey, Geo. Wood, 

 and Beulah M. Rhoads were elected members. 



The Committee to which it had been referred recommended the 

 following paper to be published. 



