I 287 ] 



therefore commonly fpun. We fear that M. Ly- 

 man is rather fanguine in thuYking that the culture 

 of the Silk-w0rm may fucceed in fo northern a cli- 

 mate as Sweden, 



75. MiGRATioNES Avium. C. D. Ecmark, 1757. 



This paper is confeiTedly one of the moft com- 

 plete that has been publifhed on this curious fub- 

 jed, which is yet involved in confiderable obfcu- 

 rity 5 the caufe of thefe migrations, virith refped to 

 feveral birds, and the places of their refort, being 

 yet unknown. With refped to the greater number, 

 it cannot be doubted but that the facility of find- 

 ing their appropriate food in diftant countries, in 

 the different feafons, and their fecurity during in- 

 cubation, have the principal lliare in this part of 

 their economy. 



Mr. Ecmark obferves, that the greater number 

 of migrating birds belong to the flat-billed order 

 (Jnferes), particularly to the Goofe and Merganfer 

 genera •, and to the Waders, ( GralU) : the former 

 moftly breed in the extreme north, where, from 

 the relation of Linn^^ius, their number almoft 

 darkens the air, and they are driven fouthward by 

 the freezing of the lakes and rivers. Numbers 

 alfo of the fmall- billed birds (Pafferes)^ efpecially 

 thofe with flender hiUs^ are of the migrating clafs. 

 The infe5livorous retire fouth wards when our winter 

 advances, as others in that feafon vifit us for the 

 fake of berries. 



It is no fmall merit in Mr. Remark^ that in this 

 paper he brings together, in one view, more com- 

 pletely 



