The Lilies of France

A study of the incubation periods of birds; what determines their lengths, by W. H. Bergtold ...

“…The structure of the^^g lends itself to resistance to too rapid cooling, for the shell, with its small "pores" full of air, and the shell membrane, together, make a good insulating medium. Brehm (quoted by Ingersoll,110), says it requires one hour and forty-five minutes at fifteen degrees, Fahrenheit, to freeze a living Qg,g\ this means that it takes seventeen degrees, Fahrenheit, of frost for nearly two hours' exposure, to kill the developing embryo, and it is apparent that this time may vary proportionately with the size of the egg. It is Avell known that eggs in the later stages of incubation cannot resist successfully such low, or prolonged low, temperature as just mentioned, but that they do successfully withstand milder degrees of frost for much longer periods, especially during the early days of incubation, is equally well known.…”

“…The cuckoo is said (110) to lay eggs which are, proportionately to itself, the smallest of all birds' eggs; has this arisen because of the possibly higher temperatures of the foster parents?…”

“…It seems to me that these questions can be answered only in the affirmative. If it be true that the number of eggs laid in a set is in direct ratio to the dangers encountered by the species (110), it also would seem reasonable to believe that a species would be better able to successfully maintain its status in the face of its daily dangers, through the increased prolificity made possible by the short incubation period permitting more, and perhaps equally large broods to mature during the breeding season; this is but another way of making the eggs proportionate to the dangers meeting the species in its daily life, and may be looked upon as a result of the higher birds having high temperatures.…”

Developmental instability in German Iris flower as a potential biomonitoring method

“…It blooms mostly in May-August, the perianth color is blue, violet, yellow, brown or white, with various patterns of pigment distribution [46]. This species has been extensively developed as an ornamental plant [47,48]. In addition to its ornamental value, German iris rhizomes contain an essential oil often used in cosmetic and perfume industries [49,50].…”