The fibrils of the outer coat also show the change to a less extent, while the degeneration very rarely spreads to the middle coat.
While there is a general tendency in the group to mucilaginous degeneration of the cell-wall, in Laminaria digitata there are also glands secreting a plentiful mucilage.
A survey of the vegetable kingdom indicates that evolution has proceeded, on the whole, from the simple to the complex; at the same time, as has been already mentioned, evidence of reduction or degeneration in common.
But the practitioner must be assured that neither valvular lesion nor degeneration of the myocardium is present.
Fatty degeneration is a retrogressive change associated with the deposit of fatty granules or globules in the cytoplasm, and is caused by disorganized cellular activity (figs.
On the whole, then (though degeneracy, as well as progress, is a force in human evolution), we are not tempted to believe in so strange a combination of forgetfulness with long memory, nor so excessive a degeneration from common sense into a belief in the personality of phenomena, as are required no less by Spencer's system than by that of Max Muller.
When a nerve-trunk is separated from its central connexion, the distal portion falls into a state of fatty degeneration (Wallerian or secondary degeneration).
As might be expected, degeneration in larval structure is correlated with a concealed habit of life.
This term is usually applied to a semi-solid substance of homogeneous and gelatinous consistence, which results partly from excretion and partly from degeneration of cellular structures, more particularly of the epithelial type.
But, as will be pointed out later, organs are often found to have undergone degeneration or reduction, and such reduced or degenerate structures may easily be mistaken for primitive structures, and so the investigator may be misled.