ISSUED IN BEHALF OF THE SCIENCE WHICH IT ADVOCATES. 



Volume 111, 



JANUARY, 1878. 



Number 11. 



Oological. 



^ROM a short review of a fresh collec- 

 tion of eggs uow before me, repre- 

 ^l- senting most of the known types, and 

 largely duplicated in its local genera, let us 

 see if Ave cannot derive some hints worth 

 knowing. 



The English eggs on the whole Avould 

 seem to be of the dullest cast, though pre- 

 senting many types conformable to our 

 own. The African sets are the fewest in 

 number, of course, even including tl)e sea- 

 birds' eggs. But South America presents 

 us with the showiest lot, as perhaps should 

 be expected from its immense avi-fauna — 

 the determined species of five -thousand 

 dwarfing our list of several hundred. The 

 darkest egg noticed is the Emu's, and the 

 strangest that of a South American Par- 

 tridge {Not/mra 2-)erdicaria) , which is of 

 a heavy purple hue, but so glossy it reflects 

 like a mirror : indeed, it is hard to make 

 people believe the polish is not artificial. 



But we cannot here review the oology of 

 the world ! It is proposed, however, as 

 briefly as may be, to speak of the interest- 

 ing changes to be observed in any extended 

 series of North Ainerican eggs. From fif- 

 ty sets of Terns' eggs shown in this collec- 

 tion, taken on Wycopesset Island, July 15, 

 1876, one egg only is plain — resembling a 



Cooper's Hawks'. From three -hundred 

 sets of Terns' eggs, taken on Gull Island, 

 L. I. Sound, July 15, 1877, very few show 

 the sub-shell markings of second or third lit- 

 ters, one only appears to be of half size, and 

 there is a single plain egg of a fine sky-blue. 

 From a big " rookery" of Crow Blackbirds 

 on Fisher's Island, the groundwork ofthe 

 eggs exhibited ranges from gray to blue and 

 green, and again we find one only from the 

 series to be plain and blue as the egg of a 

 Robin. Thus are shown eggs of birds com- 

 monly covered with markings absolutely 

 plain. Now and then we see eggs normal- 

 ly plain, with decided markings. Here are 

 sets of House Phebes' and Least Flycatch- 

 ers' with small black specks. Here are 

 three sets of Marsh Hawks', all from the 

 same pair and all plain. Yet I know of 

 four sets with markings in the reserve col- 

 lection of one naturalist. Here are three 

 I sets of Cooper's Hawks' eggs plain, and one 

 i spotted. A pair of Cooper's Hawks, rob- 

 1 bed many times in Rockwell's Woods, Nor- 

 wich, Conn., always laid spotted sets, the 

 spots looking like small blotches of bronze. 

 \ Dr. Brewer says that any bird laying plain 

 eggs is liable to deposit lymph upon them. 

 i How about the Woodpeckers' eggs, which 

 ! are never by any chance other than plain ? 

 ' Because their shells are transparent, and 

 no lymph is used in their composition? 

 ' But I find that a Cooper's or a Marsh Hawk 



