The “Flat Earth Society” 

And Why Quail Eggs Made Me Think of It

It seems impossible to believe that there are still people, who believe the Earth is flat. However, these people are even organized in “Flat Earth Societies” and one of their ridiculous arguments is that on maps the entire Earth is shown in two dimensions on a flat piece of paper. However, how the surface of a spherical object can be ‘spread out’ and presented in two dimensions is, of course, something one learns in Geography lessons in connection with the Flemish cartographer Gerardus Mercator. But there are numerous other methods that have been suggested (and are being used) to “flatten out” the surface of the spherical Earth. Some result in areal distortions while others present areas correctly, but contain other, namely angular distortions or are difficult to read and comprehend.

I became interested in these various methods when my colleagues at the Physiology Department in Oulu, who in their experiments used quail birds   – lots of them in fact-   regularly gave us fresh quail eggs that we then boiled and ate during our tea (or in Finland ‘coffee’) break. Quail eggs are about one fifth the size of a chicken egg, are of mottled appearance and contain a rich-coloured orangey yolk. But what I found most amazing by comparison with chicken eggs was the fact that not a single quail egg resembled another quail egg: they all looked different from each other. The two extremes were that some eggs were almost completely white-shelled, while others were almost completely covered in dark-brown patches with little white areas in between. Most of the eggs were speckled with totally randomly distributed dark and white blotches of different shapes and sizes. Patches like these, as in other ground-nesting birds with speckled eggs, indicate slightly thinner and thicker shell regions, with reddish-brown haemoglobin-derived protoporphyrins being the responsible pigments.

Thinking of the near spherical Earth and wanting to compare the extent of dark and white areas in different quail eggs, I wondered how we could possibly “flatten” a quail egg mathematically (or photographically) and then quantify the amounts of white and dark. Ideally one should be able to construct a system to readily identify the positions of some notable spots on the shell (similar to the longitude and latitude used in locating places on Earth). I discussed the problem with a biophysicist and initially he was quite optimistic and enthusiastic about the idea, but quickly gave up once he fathomed the complexity of the issue. Quail eggs are not spherical: they are egg-shaped and not all eggs are of the same dimension. Where would you place the North and the South Pole and how would you be able to scan the entire surface from pole to pole without sophisticated electronic equipment and computer programmes to eliminate inaccuracies and distortions? 

This project of mine was never completed, but I still believe it had merit  –  and can be useful not just for quail eggs. There are many species of birds, not just quails, which produce eggs that do not resemble each other, but sport differences in surface markings. Are there certain regular or persistent patterns regarding the placements and sizes of these surface features? Can they be quantified and can the data then be related to the age, the nutrition and health status of the egg-layer? For that to be possible, a reliable method to identify and measure the blotches on the surface of the egg has to be developed. To be honest, I do not know if someone has by now developed such a technique to photographically or electronically flatten the surface of an egg, but I still think it was an interesting idea that came to me, helping myself to heaps of hard-boiled and tasty quail eggs during tea-breaks (sorry ‘coffee breaks’) at the “Oulun Yliopiston Fysiologian Laitos”.  

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

biology zoology blog frog egg embryon (1)

A Frog’s Egg

What can a frog’s egg teach us

Hardly anything in zoology could be more exciting than to observe how from an egg cell a whole new individual develops. Unfortunately for the curious person very often the developing egg is hidden from view as in mammals and sometimes it is so small that it is impossible to examine what precisely goes on. But there are some animals which allow even children without the aid of a microscope to observe the embryo and how it grows inside the egg. One example are freshwater pulmonate snails like Planorbarius corneus (the ramshorn snail) or Lymnaea stagnalis (the common pond snail). Their eggs, attached in clusters of up to 40 or so on the glass walls of an aquarium make observations easy. But other, and even bigger and therefore more suitable eggs allowing one to follow the changes that go on inside them are those of frogs, toads and newts. In the gelatinous eggs of these amphibians, rice grain sized in newts but up to the size of peas in frogs, one can see the entire developmental process through the transparent egg membranes virtually with the naked eye (although a hand lens would help, of course).
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penguin easter egg meyer rochow nutrition

Easter post : The Avian Egg : Brittle, Delicate, yet Firm

The Egg : Nutritious and perfectly shaped

We are easily fascinated by the largest, fastest, strongest, ugliest…., well superlatives generally and when you examine animal tissues, you can, of course, classify cells according to their size, shape, volume, etc. The longest cells in the human body are, no doubt, certain nerve cells with their projections called axons. In the giraffe or in a whale such neurons may easily be several metres long. But the most voluminous cells overall is nowadays, after the demise of egg-laying dinosaurs, the bird egg. And while we are at it: the smallest eggs, only 1 cm in length and 0.37 g in weight, are laid by the Jamaican hummingbird Mellisuga minima.

An unfertilized egg of a bird is a single cell (tasty and nutritious), with one nucleus and a massive amount of yolk. The semi-liquid egg content is contained in a wonderwork of porous lime on a matrix of interwoven organic fibres, which together (lime and organic fibres) make up the egg shell. The shape of the egg is marvellously practical – not only from the point of laying it, but as a compromise to strength and durability. Egg shells are often cryptically coloured and therefore less conspicuous; they also have to be sufficiently strong to resist predators. But the shell’s most important task is to prevent the semi-liquid content from oozing out through the tiny pores in the shell, but at the same time allowing gas exchange of the breathing embryo inside the egg to take place without leading to water loss, i.e., dehydration. It was shown that pigeon eggs laid under very dry conditions, exhibited 30-40% less water evaporation pressures (correlated with the total number of gas exchange pores and a greater shell thickness) than eggs, which were laid under conditions in which the relative humidity of the air was not elevated and I have found that penguins also lay eggs with relatively thick egg shells, perhaps in response to the dry Antarctic climate.

On the blunt end of each egg is an air chamber whose physiological role in respiration and internal humidity control only recently has been worked out. Although present day ostriches lay by far the biggest eggs, extinct New Zealand moas had larger eggs still and the “elephant bird” Aepyornis of Madagascar, which died out only about 350 years ago, even laid eggs that weighed 10 kg, were 34 cm long and had a volume of 160 chicken eggs. There is, however, an upper size limit for an egg, because a greater volume requires thicker and stronger shells and one arrives at a point, where a hatching chick simply would not have the power to escape from its cradle – unless the parent bird helped by breaking the egg from the outside.

Eggs are a powerful symbol of life, growth, love and fertility and they play a variety of cultural roles: famously decorated Fabergé eggs come to mind; eggs as wedding gifts (the Romans knew: “omne vivum ex ovo”), but also as a food item to be avoided (by Brahmin Hindus, for example). Northern Australian Aborigines, however, are known to have feasted for weeks almost entirely on eggs during the breeding season of the magpie goose and at Easter finding, collecting and eating eggs, maybe not for weeks, unless they are made out of chocolate, is still lots of fun – that is if you are not Chinese and prefer egg jam or eggs buried for a few months in the soil with clay, ash and salt until they smell so beautifully mature and shine so deliciously enticing in sullen brown, green and purplish hues when cut in half!

penguin easter egg meyer rochow nutrition

Is Ayu waiting for the thick shell penguin egg?


© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2016.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.