In the more highly developed series, the mosses, this last division of labor takes the form of the differentiation of special assimilative organs, the leaves, commonly with a midrib containing elongated cells for the ready removal of the products of assimilation; and in the typical forms with a localized absorptive region, a well-developed hydrom in the axis of the plant, as well as similar hydrom strands in the leaf-midribs, are constantly met with.
The excretory system is highly developed and opens at the posterior extremity by a paired muscular bladder.
In the more highly developed lorms, as already indicated, the leaf-trace is split up into a number of strands which leave the base and sides of the leaf-gap independently.
These properties are most highly developed in the substance known as jet, which is a variety of cannel found in the lower oolitic strata of Yorkshire, and is almost entirely used for ornamental purposes, the whole quantity produced near Whitby, together with a further supply from Spain, being manufactured into articles of jewellery at that town.
The simpler forms bear the perithecia directly on the mycelium, but the more highly developed forms often bear them on a special mycelial development - the stroma, which is often of large size and special shape and colour, and of dense consistence.
Its antiquity is not, indeed, comparable to that of ancient Egypt or Greece, but no country besides Japan can boast a living and highly developed art that has numbered upwards of twelve centuries of unbroken and brilliant productiveness.
In commerce it had to compete with the highly developed maritime industry of Great Britain.
The struggle of the future must inevitably be between a number of great nations, more or less equally well equipped, carrying on production by the same general methods, each one trying to strengthen its industrial and commercial position by the adoption of the most highly developed machinery, and all the methods suggested by scientific research, policy or experience.
The mammal fauna of the Indian region of Asia is much more highly developed than that of the Palaearctic. The Quadrumana are represented by several peculiar genera, amongst which are Semnopithecus, Hylobates and Simia.
This concentration and obliteration of somites, often accompanied by dislocation of important segmental structures (such as appendages and nerveganglia), may lead to highly developed specialization (individuation, H.