52 THE PASSENGER PIGEON IN PENNSYLVANIA 



They were hemmed in. They could not reproduce 

 themselves on other food. The attrition progressed 

 and their lines of supply were shortened, as the cleared 

 helds became more numerous, or as forest fires de- 

 stroyed the prolific beech trees. 



Where the beech forest flourished the soil was most 

 fertile and easily cleared for the first crops of agricul- 

 ture; grass for pasturing the domestic animals upon 

 grew luxuriantly among the stumps of trees removed ; 

 the stumps soon rotted and were readily removed for 

 better crops and convenient cultivation ; the soil had 

 been made rich by the detritus of tree-life that had 

 been discharged yearly for centuries, and the farmers 

 coveted the land ; so the beech forests became smaller 

 and more exposed to rapacious man. Three million 

 farms were cleared in the forests where their food 

 grew most abundantly and the birds fell as victims to 

 their direst foe, the men who occupied these farms and 

 sought a profit from the nurseries of the passenger 

 pigeons to compensate them for the crops that had 

 been devastated in their fields by the hungry flocks. 



The farmers were never friendly to these questing 

 birds when they returned, as the Indians had always 

 been. No doubt, the passenger pigeons were the chief 

 agency, in some mysterious way, for spreading the 

 seed germs of the beech, as another, closely allied va- 

 riety of pigeons, did for the nutmeg trees, in another 

 part of the world. The passenger pigeons shrank in 

 numbers, as did the bison on the plains ; but no one 

 realized that a race was being exterminated ; and even 



