26 



THE OOLOGIST 



property and the natural result of a union 

 of two different species. P^ven if this is 

 not in accordance with the laws of physiol- 

 ogy, there is an interestiu<^ item in the 

 knowledge that, at least one, and probably 

 two of the eggs, were clearly abnormal, 

 Avhich luct is made additionally prominent 

 and notewortliy by the circumstances sur- 

 rounding the whole matter. The inference 

 we drew — much less a theory — was the re- 

 suit of reflections brought out by the cir- 

 cumstances ; and, excepting the possibility 

 of an abiu)rmal e^^'j: being the natural con- 

 sequence of an "• abnormal " pair of bii'ds, 

 it follows that this may be, and very prob- 

 ably is, an instance simply of abnormity, 

 even though brought about by a different 

 species. The rule that eggs of the same 

 species the world over, are of the same gen- 

 eral appearance, and the exception that 

 they occasionally widely differ in all re- 

 spects, may apply to the production of a 

 pair of birds of which the male is one spe- 

 cies and the female another, as well as to 

 a pair of like species. And, among the 

 causes of abnormity in eggs, it is reasona- 

 ble to suppose that a union such as indi- 

 cated, might combine opposite character- 

 istics, which, together with the attend- 

 ant physiological relations of each, would 

 produce a defective egg. 



While we are on the subject of abnormi- 

 ties, an item from a correspondent in New 

 Jersey will be of interest. Reference is 

 also made to Dr. Brewer's opinion of im- 

 maculate eggs, where usually maculate, and 

 vice versa, in our April number. 



A Plain Egg. 



On reading your article published in The 

 OoLOGisT, (May issue) entitled, "A Non- 

 descript Egg," puts me in mind of a simi- 

 lar circumstance that happened with me 

 last year. I was out one day on a collect- 

 ing tour, when my brother called my atten- 

 tion to a nest situated in the top of a pine 

 tree, and he said he had seen some Crow 

 Blackbirds about there a few days before. 

 I climbed up the tree and was much sur- 

 prised to find a nest, to all appearances ex- 



actly like a Crow Blackbird's, but the eggs 

 (three in number) were very peculiar to 

 that species. One was marked like a Crow 

 Blackbird's, and the other two were the 

 same shape and measurements, but were of 

 the ground color of the first. One of them 

 had a black spot on one side, the other was 

 plain. J. L. Adams, Jr. 



Notes on the Nesting of the Black 



Tern, at St. Clair Flats, Mich., 



June 7, 1878. 



BY W. H. COLLINS. 



T^HIS species builds a nest of short pieces 

 of grass and rushes, laid together in a 

 little heap on the drift rushes, in sheltered 

 situations where the wind cannot carry them 

 away. Many were placed on pieces of 

 board and drift-wood that were floating in 

 the marsh. The eggs were usually three ; 

 I did not find more in any of the nests. 

 Some of them were fresh and in others in- 

 cubation was well advanced. The birds 

 were very courageous in defending their 

 nests ; they would sometimes come so close 

 to my head that I could feel the wind from 

 their wings, while they kept up a continu- 

 ous cry. Most of the eggs were warm 

 when taken ; still, I did not see any of the 

 birds sitting on the eggs. The female birds 

 killed showed that they were sitting, by the 

 bare portions of their bodies and the thick 

 skin usually found on birds that are sitting. 

 1 often saw the birds go down in the rush- 

 es and remain until I got within several 

 rods of the place, when they would rise 

 and hover over the vicinity, and I usually 

 found a nest near by. In one instance, I 

 found two nests on one piece of drift-wood, 

 twelve feet long, one nest at each end ; us- 

 ually the nests were not witliin sight of each 

 other. While the birds were there by hun- 

 dreds, I frequently killed two birds at one 

 shot, and could shoot for an hour without 

 changing my position. The birds kept com- 

 ing at each discharge of the gun, which 

 seemed to excite and not frighten them. 



