10 



THE OSPREY. 



following^: "That among- the vertebrated aiii- 

 tnals, the eggs of birds, of reptiles, and of tish. 

 present in their composition dilToronoos which 

 the simplest analysis cannot mistake, and be- 

 sides that the eggs of Sauria and ()i)hidia bear 

 great analogy to those of birds, while the eggs 

 of Batrachia resemble those of the cartilagin- 

 ous fishes"*. This conclusion is the more note- 

 worthy as it did not lead the observers to recog- 

 nize the heterogeneity of their class of reptiles, 

 the true reptiles and tlio amphibians being still 

 combined in the one class. 



Within the class of birds, the French savants 

 found noteworthy differences. For example, say 

 they. "In examining the white taken from eggs 

 of differcTit kinds of birds, we have often noticed 

 that this body has varying properties. In some 

 kinds, it is almost fluid, in others it possesses 

 a gelatinous consistency'. The white of the egg 

 of a hen is, after boiling, opaque and of a pure 

 color, white and solid. That of the lapwing be- 

 comes after cooking, transparent, opaline, 

 greenish, and so hard that it maybe cut into 

 little stones, used in certain parts of Germany 

 for common jewelry"'+. 



These extracts may furnish hints as to points 

 to be observed. The study of chemical details 

 would demand special training- and experience, 

 but some physical characteristics might be in- 

 vestigated by ordinary observers using proper 

 care and precautions. Such are the absolute 

 and relative time required bj' the white and 

 yellow to become hard in boiling, the degree of 

 hardness acquired, and the behavior of the white 

 and vellow to reagents. 



There is much room for investig^ations of this 

 kind, i\}h\ scarcely any attention has been paid 

 to the subject by oologists. Chemists have done 

 considerable in the way of analysis, but the 

 want of comparative method renders their con- 

 tributions of little value for the zoolog'ist. If 

 we could have such an luiion of the zoologist and 

 chemist as was accomplished in the case of the 

 investigations by Valenciennes and Fremy, 

 with modern methods, we might undoubtedly' 

 have a rich harvest. 



The edibility and taste of eg'g's of different 

 kinds would als(^ be interesting" subjects for in- 

 vestig'ation, some being repulsive or even inju- 

 rious as food, although most are regarded with 

 not very unequal favor. It is noteworthy that 

 the eggs of some fisheating birds are often 

 blamed for a fishy "taste". The "taste" so 

 called, however, is subjective rather than ob- 

 jective. In other words, the taster, knowing 

 the source of the eggs and the habits of the 

 bird, attributes the peculiarity of flavor to the 

 food, and therefore calls it "fishy" whereas it 

 is really differentiated from the normal flavor — 

 that of the hen's egg — in an inidefinable 

 way. 



Unfortunately, we have as yet no gustometer 

 (or measurer of taste) and consequently' the 

 results of inquiry would be expressible to a con- 

 siderable degree in terms of the imagination 

 rather than exact science. Some interesting 

 results, nevertheless, migiit be obtained by judi- 

 cious observations. 



Letters. 



FLIGHT OF AMERICAN GOLDFINCH. 



EniTOR OF THE Ospkey: 



Noticing a question some time ago b)' Mr. 

 Walter Deane. of Cambridge, Mass. , as to whether 

 the statement on page 213 of "Citizen Bird," bj' 

 Mrs. Mabel Osgood Wright and Dr. Cones, that 

 the American Goldfinch utters its flight-call "on 

 every down-grade curve,"" were not a mistake, 

 I took particular pains to settle the matter for 

 my own satisfaction during last summer. On 

 page 287 of his excellent handbook, Mr. Chap- 

 man has the bird very graphically represented 

 as uttering his notes on the downward curve; 

 nevertheless my observations showed that this 

 call is always uttered on the up-grade. I find 

 reference to support this in Mr. P. M. Silloway"s 

 "Sketches of some common birds,"" where Gold- 

 finches are described as "bounding upward with 

 waving wings, and curving downward with 

 folded pinions, uttering their short measures as 

 fhey rise with the movements of the wings." In 

 fact, I think it will be found to be quite a general 

 j-ule with birds that have this intermittent or 



up-and-down flight, that their notes, when the)' 

 have any in flig'ht, are emitted at tlie time the 

 wings are in use. I was rather interested to 

 know what some of the older ornithologists said 

 about this habit of the Goldfinch, or whether 

 the)' said anything at all, and to show what 

 minute and accurate observers some of the 

 pioneers of American ornithology were, I will 

 give what I found in two instances. To cjuote 

 from Wilson: "Their flight is not direct, but in 

 alternate rising's and singing's, twittering as 

 they fly, at each successive impulse of the 

 wings;"" and Audubon says, "The flight of the 

 American Goldfinch is exactly similar to that of 

 the European bird of the same name, being 

 performed in deep curved lines, alternately 

 rising and falling', after each propelling' motion 

 of the wings. It scarcely ever describes one of 

 these curves without uttering" two <jr three notes 

 whilst ascending, such as its European relative 

 uses on similar occasions." 



Leon J. Cole, 

 .///;/ Arbor, Mich., Apr. 7, 1899. 



*Am. Journ. Sc. and Arts (2), Vol. xx, p. 71, 1855. 



+Am. Journ. Sc. and Arts (2), Vol. xix, p. 40. 



