No. 5S6] SHORTER ARTICLES AXD DISCUSSION 647 



Among the conclusions of this paper, which pretty well i 



lid widely dis 



A discussion followed in winch Professor Morse. C. V. Riley, 

 Professor Gill and Asa Gray took part, but although some agreed 

 that there was no reason why marked changes and gradual modi- 

 fications should not both play a part in evolution, yet the tend- 

 ency was rather to look upon the former as sports which were of 

 little evolutionary significance. Meehan afterwards referred to 

 this paper as showing that : 



as far as human knowledge had yet reached, as had been the surround- 

 ing circumstances of the parent form. 



Quotations of a few of Meehan 's other papers, with notes upon 

 them, will serve to show the range of his ideas and the accuracy 

 of his observations. 



"On the Agency of Insects in Obstructing Involution," Proc. 



Phila, Acad., 1872, 235-37, 1872. 

 "On Rapid Changes in the History of Species.'* Proc. Phila. 



Acad., 1884, 142-43, 1885. 

 "Persistence in Variations Suddenly Introduced," Proc. Phila. 



Acad., 1885, 116, 1886. 



We see that identical forms may appear simultaneously in localities 



"On a White-seeded Variety of the Honey Locust," Proc. Phila. 

 Acad., 1885, 404, 1886. 



In this paper he describes a tree of Glcditschia triacanthos 

 growing near Germantown, Pa., which had seeds white instead of 

 dark olive-brown. They also differed in shape, being nearly 



