The gelatinous or creamy mucilage of which these fungi consist, forms a mycelium which is either diffuse, or creeps over the matrix on which it grows in anastomosing filaments like a network, or it is arranged without any definite order. This spawn gives rise to many bodies having an envelope of one or more concentric membranes, technically called a peridium, enclosing a gelatinous fertile substance which, when mature, becomes a mass of scales or threads mixed with spores; the spores are mostly attached to short threads singly or in groups, sometimes surrounded by a firm coat or cyst. These bodies are either sessile on the mycelium or stalked, and are either free or confluent. In their soft state the tissues are so delicate that they exhibit no structure, but just as they are passing from the puffy to the dry dusty state there are indications of it. It would be tedious to describe the variety of forms assumed by the fruit-bearing bodies in the different genera of these fungi, or the manner in which they are ruptured to give egress to the spores, which differ in colour according to the species, though they are for the most part red. The forms of the chaffy scales and threads are equally diversified: in the species of Trichia, the threads contain one or more spiral filaments, a form peculiar to the vegetable kingdom. Botanists are now generally of opinion that the Myxogastres are vegetables, although the singular Amœba-like motions some of them exhibit, and the nature of the motile bodies they produce, seemed to assign them a place in the animal kingdom; indeed, even now little is known of the reproduction and final life-history of these singular fungi. Motions precisely similar to those of the Amœbæ, the lowest class of animal existences, were observed by MM. Hoffmann and Tulasne, and more especially by M. de Bary,[53] in the Æthalium septicum. It is a yellow pulpy mass, produced upon a spawn or mycelium consisting of semi-fluid gelatinous anastomosing filaments, often widely spread through the moist tan in hothouses. M. de Bary describes the filaments of the mycelium as full of a multitude of small colourless corpuscles mixed with large yellow ones; moreover the branches of this mucous network are described as continually changing their form, in a manner closely resembling the pseudopodia of the animal Amœba. They push out new branches, others are withdrawn, and the whole mycelium frequently advances with a creeping motion of translation. The yellow pulpy mass produced by the mycelium is entirely composed of similarly constituted soft filaments about the thickness of a bristle closely interlaced. They anastomose in all directions, in long or short meshes, and their upper free extremities form groups of projections which bristle the exterior surface of the pulpy mass.