254 BULLETIN 195, UNITED STATES NATIONAL MUSEUM 



When the young are small the faecal material is deposited in the bottom of the 

 nest. As the nestlings increase in size, however, they maneuver about until they 

 assume a position facing away from the entrance, and the dropping is ejected 

 on the periphery oi .he nest. During the later period of nest lile the young 

 succeed in ejecting the excrement witli such force that it is carried over the side 

 of the nest and drops to the ground. * * 



Other waste materials, such as eggshells, infertile eggs, or any young 

 that might die in the nest are carried away. The young increase in 

 weight very rapidly, from about 0.87 gram at hatching to about 11.08 

 grams at the end of the twelfth day. Meantime the nest has become 

 enlarged and worn as the young increase in size. The young may 

 leave the nest on the twelfth day, if disturbed, but normally not mitil 

 the fourteenth day. Occasionally one will return to the nest for shel- 

 ter, but they usually spend the nights perched in the dense flags. The 

 parents care for them for at least 2 weeks, though after the first 10 

 days they are able to secure some of their own food. The family group 

 remains together through the summer and wanders about at some 

 distance from the nesting place. 



It seems to be the consensus that two broods are raised in a season, 

 but not a third. Dr. Welter ( 1935) found no evidence of a third brood, 

 "The female begins her second nest about 2 weeks after the young of 

 the first have left the nest. The majority of the nests, then, in the 

 regions' studied would be started between July 15 and August 1, with 

 the last week in July the most active period." Probably while the 

 female is building the second nest the male is busy with the first brood 

 and is not very active in building dummy nests. 



PluTMiges. — Dr. Welter ( 1936) has published another excellent paper 

 on the development of the plumage in the young marsh wren and on 

 subsequent molts, to which the reader is referred for details ; it is fully 

 illustrated with drawings and photographic halftones. It is evident 

 from the photographs that the young bird is practically fully feathered 

 in the juvenal plumage before it leaves the nest, though the wings are 

 not fully developed and the tail is still rudimentary. Dr. Dwight 

 (1900) says that the natal down is white. In the juvenal plumage 

 the young wren is much like the adult, but the crown is uniformly dull 

 black, without the dividing brown area ; the white streaks on the back 

 are very faint or lacking ; and the white superciliary stripe is indistinct. 

 Dr. Dwight says that the first winter plumage is "acquired by a partial 

 postjuvenal molt beginning about the middle of August which involves 

 *^e body plumage, the wing coverts, probably the tertiaries, but not the 

 rest of the wings nor the tail," young and old becoming practically in- 

 distinguishable. Dr. Welter ( 1936) differs from Dr. Dwight, as to the 

 extent of this molt, saying : "Juvenals collected during the fall of 1931 

 which are now in the Cornell Collection show a molt of both rectrices 

 and remiges." These two authorities also differ as to the prenuptial 

 molt. Dr. Dwight says that the nuptial jplumage, in both adults and 



