1G TRANSACTIONS OF THE 



and the successive stages of probable evolution, from the 

 tunicate type upwards, indicated. 



The conclusions from the data at hand were given as fol- 

 lows : 



In fine, we are compelled by the force of the evidence to 

 recognize a close relationship with the apes, and to admit 

 the probability of our derivation in common with the 

 Chimpanzee and Gorilla from a common ancestor, which 

 must have been very like the latter animals. The different 

 stages through which man was evolved and became differ- 

 entiated can ever be surmised with much probability. Our 

 pithecoid ancestors doubtless began at length to resort, more 

 and more, to the use of their hands for various purposes 

 and among others for the employment of weapons of offense 

 and defense. The shorter arms would then be more efficient 

 than the long ones of the primitive primates and their 

 abbreviation would therefore ensue. The more the hands 

 were used for grasping, and discontinued for progression, the 

 more delicate they would become. The withdrawal of the 

 fore members from locomotion, and the continuous assump- 

 tion of an erect attitude and balancing thereby would entail, 

 among other characters, a sigmoid flexure of the vertebral 

 column and a development of the muscles from the buttocks 

 and calves. The same cause, in combination with the 

 specialization of the hands, and the more exclusive use of 

 the feet for walking and sustaining the whole body, would 

 in time result in the parallelism of the great toe with the 

 other. Concomitant with all these modifications would be 

 the reduction of the canine teeth. These being, finally, 

 comparatively little used as weapons of warfare or for pro- 

 curing food, would gradually become reduced in size, and at 

 length little protuberant beyond the others. The diastemas 

 in the opposite jaws being then useless the same would shrink 

 and the rows of teeth in the upper as well as the lower become 

 continuous. There would then, also, be no need of the 

 powerful temporal and masseter muscles, and consequently, 

 they would shrink in size, and with them would, likewise 



