There is even a little treatise from the hand of Milton, published two years before his death, called Artis Logicae Plenior Institutio ad Petri Rami Methodum concinnata.
Asplanchnopus myrmeleo, showing horseshoe-shaped germarium (left), blind saccate stomach (right), apical bladder, foot, &c.; g, Asplanchna ebbesbornii - the coiled tube at left is a kidney; h, i, incudate jaws of Asplanchna brightwellii and girodii chiefly formed of rami, with the rudimentary mallei parallel and external to them; j, Ascomorpha hyalina.
Thus, when acting as swimming organs, the appendages, or their rami, are more or less flattened, or oar-like, and often have the margins fringed with long plumose hairs.
When used for walking, one of the rami, usually the inner, is stout and cylindrical, terminating in a claw, and having the segments united by definite hinge-joints.
When specialized as bearers of sensory (olfactory or tactile) organs, the rami are generally elongated, many-jointed and flagelliform.