256 Union Bay 



occupied in the communities, but it gives little indication of 

 the progress of knowledge about them. The advance must 

 have been slow. There could have been little accumulation in 

 those dull and unreceptive centuries which followed the pe- 

 riod of Rome's greatness and accompanied its decline. Re- 

 ligious thought not only dominated but almost displaced 

 scientific thought. Study became mere routine and was con- 

 stantly interfered with by the religious authorities. The Greek 

 manuscripts lost their standing and were seldom read. The 

 Physiologus and the bestiary, first intended to describe nat- 

 ural subjects, became merely moral comments on real or 

 mythological animals and without scientific value. 



This is no place for a lengthy report on the progress of the 

 next centuries. Here and there great figures appeared, some 

 like Neckam and Albertus Magnus to revive interest again 

 in the early philosophers; and others, from early in the six- 

 teenth century, to begin work in various fields and to set the 

 stage for modern science. Several books on birds were 

 brought out, promising in that they contained some material 

 based on personal observation, but still including many state- 

 ments from the old traditions. The time came when the 

 astronomy of Ptolemy was replaced by the researches of 

 Copernicus. In the first half of the eighteenth century, Lin- 

 naeus produced the Systema Naturae which catalogued and 

 methodically outlined the arrangements of plants, animals, 

 and minerals. Its later revision, by Cuvier and other men 

 who followed, resulted in a system which, except in certain 

 details, is still in use. The extension of the use of the micro- 

 scope, the emphasis on anatomy, histology, physiologv, and 

 other branches promoted the rapid advancement of biologi- 

 cal science and helped to bring it to its present state. 



Knowledge about swallows must have followed the prog- 

 ress of ornithology and accumulated slowly. It is said that 

 nearly two hundred papers and articles were written on the 

 subject of the hibernation of the birds before the theory was 



