William Carmichael McIntosh

“ Though it is quite in accurate to say that the Nemerteans have a corpusculated fluid in the general cavity of their bodies, yet a highly organised corpusculated fluid exists in their muscular proboscidian chamber, and evidently performs important functions in their economy Moreover, the remarkable proboscis and its sheath pass through a ring of nervous tissue consisting of the superior and inferior commissures and their connections with the ganglia. ”

“ The blood is probably aerated on the cutaneous, and perhaps, in some cases, on the digestive surface. The digestive system consists of a mouth opening into the anterior sucker, a muscular pharynx, oesophagus, a large stomach with various caeca! diverticula, and an anus which opens in front of the posterior sucker, though sometimes into it. In some (e.g. the common leech) , the mouth is furnished with three horny serrated teeth. ”

“ The body is more or less cylindrical, and, though corrugated, is not definitely seg mented. There is generally a protrusible proboscis, having the mouth at the end or at its base; and the anus is terminal or dorsal.
The cuticle is chitinous, has numerous processes of similar composition, longitudinal and transverse rugaa, and many pores. Beneath is a hypoderm containing certain glandular organs or sacs, and, in some, bodies like tricho- cysts. ”

“ To each the blood is carried by a branch of the dorsal vessel, which traverses the organ to its extremity, and, looping, carries the aerated fluid to the ventral vessel. Vascular loops pass between the two branches in the branchiae, and only very thin cuticular tissues covered with cilia intervene between the water and the blood, so that due oxygenation occurs. ”

“ They have cilia externally, and a cutis which secretes similar hyaline tubes to those of many Annelida. The muscular system ia greatly developed, and iu definite layers, and many swini as freely as the most active leeches. The digestive system intimately agrees, having cilia on the inner surface of the canal, a muscular cesophageal region, and a sacculated intestine, while the glandular and other elements in the wall are very similar; it differs in not passing through a buccal nervous collar, although it lies beneath the nervous system in this region. ”

“ The foregoing diverges from the arrangement in the other Annelida, since the generative products are not extruded into a perivisceral cavity, but pass outwards by a particular apparatus. The ova are deposited in capsules formed by special secretions, those of the leech being called cocoons. No metamor phosis occurs in the development of the young, which by- and-by, in some cases, attach themselves in crowds to the abdominal surface of the parent. ”

“ The anterior segments of the living annelid only are preserved, since the posterior region is apt to decay and cause the death of the whole. The natives of the Fiji group much relish a form allied to our Lysidice ninetta, and they predict its annual appearance in their seas by observing the phases of the moon. ”

“ The latter group live in earth or mud, are unable to swim or follow their prey, and have always their organs of generation. The former are elegant little worms, living in stagnant or running water, able to swim, and their generative organs are developed only at certain periods. ”

“ Many species are common to the entire North Sea, and extend to tho south as far as Gibraltar, while some northern forms enter the Mediterranean in considerable numbers. The British, species are common to the North Sea, and many range to the shores of North America. The size of some of the forms greatly increases in the Arctic Sea. ”

“ The forms frequenting the bottom of the sea live in mud or sand, or lurk under stones, in chinks of rocks, shells, and seaweeds. Many specially affect mud or muddy sand, e.g., the Lumbriconereidae, Nephthydidrse, Glyceridse, and the Terebellidse ”

“ The tubes formed by many exhibit an amount of pre cision and skill not far removed from the powers of the most ingenious insects. In common with the Nemerteans, their skin exudes a tenacious secretion which coheres under water, and this alone forms the protective tube in some ”