22 BULLETIN 196, UNITED STATES NATIONAL MUSEUM 



built under the porch, on the lintel of the front door of my summer 

 house, at Ipswich, Mass., and, at the time the book was published, had 

 been occupied, presumably by the same pair, for four successive 

 seasons. Since then it was used for two more summers, or six in all, 

 but in the winter following the last, i. e., the winter of 1906-7, it was 

 blown down, and the spot has not been built on since. I think, how- 

 ever, that the same pair have since built in a bush close to the front 

 door. This nest over the door was repaired and built a little higher 

 each year, so that in the summer of 1906, when it was last occupied, 

 it had attained a height of eight inches, and was practically a six- 

 storied nest." John H. Sage (1885) reports that "a Robin built her 

 nest five consecutive years in a woodbine that was trained up and 

 over a piazza. We knew her by a white mark on one side of her 

 head." 



Hugh M. Halliday, of Toronto, Canada, has sent us a photograph of 

 a very tall nest (pi. 2), in which at least two broods a year had been 

 raised during six successive seasons. 



Eggs. — [Author's note: Four eggs comprise the usual set for the 

 robin, but often only three are laid; five eggs in a set are rare, and I 

 have taken one set of six, and sets of seven have been reported. The 

 eggs vary greatly in size and shape; the usual shape is typical-ovate, 

 but some are rounded-ovate, elliptical-ovate, or even elongate-ovate. 

 Some are quite glossy after they have been sat upon, but usually they 

 have only a slight luster. Robin's-egg blue seems to be commonly 

 accepted as a standard color and well known; more specifically this 

 means either "Nile blue" or "pale Nile blue," as the eggs appear in 

 collections; some freshly laid eggs may be as dark as "beryl green." 

 I have seen some pure-white eggs. Almost invariably they are un- 

 marked, but I have seen one set that was sparingly marked with a few 

 small spots and dots of very dark brown ; and I have heard of a number 

 of other spotted sets, some faintly dotted with pale brown. 



The measurements of 50 eggs in the United States National Museum 

 average 28.1 by 20.0 millimeters; the eggs showing the four extremes 

 measure 31.6 by 20.3, 28.5 by 23.1, 23.8 by 18.8, and 27.9 by 16.8 

 millimeters .1 



Young. — Franklin L. Burns (1915), from the records of several ob- 

 servers, gives the incubation period of the robin as 11 to 14 days. 

 William Edward Schantz (1939), who made an intensive study of 

 three broods of robins, spending "from one to 16 hours each day in 

 direct observation," found that "incubation began in all nests the eve- 

 ning following the deposit of the second egg and lasted for 12K to 13 

 days." 



Hervey Brackbill writes in his notes: "The incubation period for a 

 marked egg was an hour or two less than 12 days." Of the nestlings 



