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Updated: June 24, 2025
In the family of the ducks, the lamellae are first used as teeth, then partly as teeth and partly as a sifting apparatus, and at last almost exclusively for this latter purpose. With such structures as the above lamellae of horn or whalebone, habit or use can have done little or nothing, as far as we can judge, towards their development.
As the smaller concretions increase in size, they come into contact and unite, thus enclosing the now functionless lamellae; and by such steps the formation of the largest concretions could be followed. Why the process regularly takes place in the two anterior glands, and only rarely in the four posterior glands, is quite unknown.
After the formation and expulsion of a large concretion, new lamellae must be developed in some manner. In one section made by my son, the process had apparently commenced, although the gland contained two rather large concretions, for near the walls several cylindrical and oval pipes were intersected, which were lined with cellular matter and were quite filled with free calciferous cells.
At present, whether the fault is in the cell proper, the conducting media, or the central center, we are unable to say. It is certainly not due to any vascular disturbances, as the skin shows no vascular changes. White spots on the nails are quite common, especially on young people. The mechanic cause is the presence of air between the lamellae of the affected parts, but their origin is unknown.
In certain species of whales there is a tendency to the formation of irregular little points of horn on the palate; and it seems to be quite within the scope of natural selection to preserve all favourable variations, until the points were converted, first into lamellated knobs or teeth, like those on the beak of a goose then into short lamellae, like those of the domestic ducks and then into lamellae, as perfect as those of the shoveller-duck and finally into the gigantic plates of baleen, as in the mouth of the Greenland whale.
This diagram shows the quadripartite arrangement of the primary septa, characteristic of palaeozoic corals, there being four principal and eight intermediate lamellae, the whole number in this type being always a multiple of four. c. Stauria astraeiformis, Milne Edwards. Young group, natural size. Upper Silurian, Gothland. Neozoic type of lamelliferous cup-shaped Coral.
Here and there in rare instances we find a few copper or bronze lamellae amongst the piles. The pottery is now of finer clay, better kneaded; and ornamentation, including chevrons, wolves' teeth, and mammillated designs, is more common. The handle, however, is still a mere projection.
I hope that I may not be misconstrued into saying that the progenitors of whales did actually possess mouths lamellated like the beak of a duck. I wish only to show that this is not incredible, and that the immense plates of baleen in the Greenland whale might have been developed from such lamellae by finely graduated steps, each of service to its possessor.
Fritz Muller states that certain species of Melita are distinguished from all other amphipods by the females having "the coxal lamellae of the penultimate pair of feet produced into hook-like processes, of which the males lay hold with the hands of the first pair."
Viewed even from this height, whence distance would do much to soften the general asperity, the surface nevertheless seemed to be bristling with its myriads of hexagonal lamellae, and to present difficulties which, to an ordinary pedestrian, would be insurmountable.
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