If the slit be narrow, so that the arc is short, the intensity is constant over a wide range, and does not fall off to an important extent until the discrepancy of the extreme phases reaches about a quarter of a period.
It is important to note that the scales are present when the moths first emerge from the pupa-case, but are loosely attached and fall off with the first flight.
The men who manipulate the stirring bars are therefore changed at short intervals, while the bars themselves have also to be changed at somewhat longer intervals, as they rapidly become oxidized, and accumulated scale would tend to fall off them, thus contaminating the glass below.
When the threads reach the air they branch in a tree-like manner, and each branch (sporangiophore) carries one or more ovate sporangia, as shown at E, E, E, which fall off and are carried by the wind.
Heart pounding, she trotted down the sloping trail, glancing nervously at the hill to make sure she didn't suddenly fall off her path.
The sepals, very rarely three, which are two in number, fall off as the flower opens, the four (very rarely five or six) petals, which are crumpled in the bud stage, also fall readily.
It is remarkable that the same tendency for the proportion of the young to fall off is perceptible in new countries as well as in the older civilizations, setting aside the influence of immigration at the prime of life in depressing the proportion of children.
The muscles suffer at an early period: they fall off in bulk, and later suffer from fatty degeneration, the heart being probably the first muscle to give way.
If not preserved in an envelope the calyptra and operculum are very apt to fall off and become lost.
When this attachment takes place by an articulation, the petals fall off either immediately after expansion (caducous) or after fertilization (deciduous).