Those cells are accurately marked, the position of which is such that the colonies, to which they give rise, can grow to their full size without coming into contact with other colonies.
This fact gave rise in ancient times to the false idea that the tapeworm originated from the union of these segments; and in modern times it has led to the view that the tapeworm is not a segmented organism (the monozoic view), but is a colony composed of the scolex which arises from the embryo and of the proglottides, which are asexually produced buds that, upon or before attaining their full size and maturity, become separated, grow, and, in some cases, live freely for a time, just as the segments of a strobilating jelly-fish grow, separate and become sexual individuals (the polyzoic view).
In the course of a few months it attains full size and maturity and probably in most cases dies in the course of a year after having given rise to another generation of larvae.
On the Grampians and neighbouring hills the larch will flourish at a greater elevation than the pine, and will grow up to an altitude of 1700 or even 1800 ft.; but it attains its full size on lower slopes.
The corm of the meadow-saffron attains its full size in June or early in July.