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of birds. No two families of vertebrates seemed to be 

 more widely dissimilar in their development, yet there 

 was a similarity almost amounting to identity in their 

 embryonic forms. He illustrated this fact, and the grad- 

 ual changes which result in the difterences between them 

 when they emerge from the eggs, by drawings on the 

 blackboard, and briefly alluded to the points of similarity 

 which are evident to a naturalist. To further illustrate 

 this similarity he described a fossil skeleton found in Ger- 

 many, which combined the wings and feathers of the bird 

 with the vertebral development and teeth of the reptile. 

 In closing, he alluded with great respect and admiration to 

 the labors of Thoreau in Concord, to which the naturalists 

 of the vicinity owe so much, and during further remarks 

 announced himself a believer in the theory of Darwin. 



Vice President F. W. Putnam gave an interesting ac- 

 count of his visit to the Indian shellheap on the river, 

 from which Thoreau made the valuable collection of relics, 

 now under his own charge at the archnjological Museum 

 at Cambridge. He was glad to have seen the place 

 where Thoreau and Wyman had collected the relics al- 

 luded to. He also exhibited and commented upon about 

 a dozen stone implements, of the shape of arrowheads, 

 which had been picked up there, some of which were 

 evidently intended for knives rather than arrow or spear- 

 heads, and gave a general account of the composition 

 and formation of the shellheaps found on" both coasts of 

 America, on many of our river banks, and in nearly all 

 other parts of the world. 



Prof. Morse, in answer to a question from Mr. Wheil- 

 don, explained how the ballooning spiders were sus- 

 pended in the air. 



