296 ICTERID^E : AMERICAN STARLINGS. 



mer visitant to New England, irrespective of locality. 

 A few indeed remain during the winter, and the spe- 

 cies as a whole may thus be considered resident ; but 

 by far the greater number, after flocking for a while, 

 in September and October, take their departure for the 

 south, to return again late in March or early in April. 

 The species of the genus Molothrus, of which there 

 are several, offer an exception to the rule of monog- 

 amy among the highly organized and morally endowed 

 families of Passerine birds. They never pair like other 

 birds, and are consequently found in loose company 

 during the season of reproduction. The female has no 

 home of her own, and probably no very close period 

 for laying. When the nesting and incubation of the 

 Warblers, Vireos, Thrushes, Finches, and most kinds 

 of orderly small birds are going on, she visits their 

 nests by stealth and leaves her unwelcome card. To 

 enumerate all the species thus intruded upon would 

 be to make out an extensive and varied list, especially 

 full in the names of Warblers, Vireos, and Finches. 

 The Summer Warbler and Maryland Yellow-throat 

 are among those most persistently victimized. As a 

 rule, the Cow-bird lays her egg with those smaller 

 than her own. The rule is also one Cow-bird egg to 

 a nest; I have found three, and others even more. 

 How many eggs may be laid by one female in a sea- 

 son is not known, and we can only suppose it to be 

 the usual Passerine number of four or five. The plu- 

 ral eggs in the same nest are presumably laid by dif- 

 ferent individuals. How cunningly Nature sometimes 

 contrives to carry out her great law without the usual 

 favoring circumstances of conjugal and parental affec- 

 tion Cow-birds being entirely devoid of these attri- 



