LAWS OF INTERNAL CHANGE 117 



1905. Wasps, Social and Solitary, pp. 811. Boston and 



New York. 



A revised and enlarged edition of the preceding ref- 

 erence. 



PIERSOL, W. H. 



1909. The Habits and Larval State of Plethodon cinereus 



erythronotus. Trans. Canadian Inst., Vol. VIII, 

 pp. 469-493. 

 Contains a useful list of references on Amphibians. 



PORTER, J. P. 



1904. A Preliminary Study of the Psychology of the English 

 Sparrow. Amer. Jour. Psychol., Vol. XV, pp. 313- 

 346. 



1906. The Habits, Instincts and Mental Powers of Spiders, 



Genera Argiope and Epeira. Amer. Jour. Psychol., 

 Vol. XVII, pp. 306-357. 



1906. Further Study of the English Sparrow and Other 

 Birds. Amer. Jour. Psychol., Vol. XVII, pp. 

 248-271. 



Includes the Vesper Sparrow, Cowbird, Common 

 Pigeon, Passenger Pigeon, and Red-headed Wood- 

 pecker. 



1910. Intelligence and Imitation in Birds, a Criterion of 



Imitation. Amer. Jour. Psychol., Vol. XXI, pp. 

 1-71. 



Studies of English Sparrow, Cowbird, Snowbird, White- 

 throated Sparrow, Field Sparrow, Bluebird, White- 

 crowned Sparrow, Fox, Song and Tree Sparrows, 

 Blue Jay, Baltimore Oriole, and Crows. 



POULTON, E. B. 



1896. On the Courtship of Certain Acridiidee. Trans. Ent. 

 Soc. London, pp. 233-252. 



REIGHARD, J. 



1903. The Natural History of Amia calva Linnaeus. Mark 

 Anniversary Volume, pp. 57-109. 



