OF EASTERN PENNSYLVANIA. :',.i 



cannot reconcile its presence in the one and absence in the 

 other, with the doctrine of progressive development. 



Let us go back from this digression, to the subject of 

 nest-building. The proper locality being chosen, both 

 birds labor diligently until the requisite materials are 

 accumulated, when the female enters the cavity, and by a 

 few bodily evolutions, gives the finishing touches to the 

 nest, which at the best is a very rude structure. The female 

 commences on the following day to deposit her complement 

 of eggs to the number of four or five. Oviposition proceeds 

 at the rate of one per day. On the day succeeding the last 

 deposit, incubation occurs, and continues for a period rang- 

 ing from 13 to 14 days. This labor devolves exclusively 

 upon the female. While she is thus engaged, her partner 

 becomes a very jealous and attentive husband, carefully 

 guarding the home from intrusion, and administering the 

 choicest articles of diet to the patient occupant with a xeal 

 and perseverance that know no bounds. 



The young are nurtured with the tenderest care until they 

 are able to feed themselves. Even then they are not driven 

 from home bv merciless parents, but continue to dwell in 

 the family, among the individual members of which the 

 most intimate love seems to exist. In this happy condition, 

 parents and children repair together, during the last week in 

 September, to the tropical climes of Central America and 

 the Isthmus of Panama. At the age of 14 days, the 

 young quit the nest, and after the lapse of a similar period 

 of time, they are able to shift for themselves. In this lati- 

 tude, but a single brood is raised in a season. 



The young are fed upon the larvae of Anisopteryx -ccniata. 

 A. pomctaria, Zeroic catcnaria, Procris Americana* Hy- 

 bcrnia tiUaria* Pieris oleracca, and various mature dip- 

 tera, such as Musca domestica, Tabanus duct us. 7\ ////- 

 cola, Culex tceniorhyucJ/n^ and Anthrax clotigata. The 

 ordinary earthworm {Litmbricus tcrrestris} i^ readily 

 devoured. The fruits of the following plants are eaten with 



