United States or Åland ? Vote for the TOP Country of the Week !
Its body, not divided into rings, is provided with about thirty pairs of fleshy tubercles, each ending in two strong claws, and the head is adorned with a pair of fleshy tubercles. It is remotely possible that some Silurian land worm, if any such existed, allied to our living Peripatus, may have been the ancestor of a series of types now lost which resulted in an animal resembling the Leptus.
Woodward, "a typical bird's 'merrythought' between the wings, and the hind leg is exactly that of a perching bird." In other words, it has the shoulder-girdle and four-toed foot, as well as the feathers, of a bird. As in the living Peripatus, therefore, we have here a very valuable connecting link between two very different types of organisms.
It is interesting to note that a form, peripatus, still exists which stands almost midway between annelids and insects and has only four segments in the head. The formation of the head was thus a gradual process, one segment being added after another. In the turbellaria the dominant functions were digestion and reproduction, and their organs composed almost the whole body.
Another favourite argument is the fact of “Pædogenesis.” Certain animals, such as Amphioxus lanceolatus, Peripatus, and certain Medusæ, are very frequently brought forward as examples of persistent primitive stages and “transitional connecting links.” But considered from the point of view of Pædogenesis, they all assume quite a different aspect, and seem rather to represent very highly evolved species, and to be, not primitive forms, but conservative and regressive forms.
First a swimming lily, Stentor, a solitary animal bloom, twenty-five to the inch; Cothurnia, a double lily, and Gonium, with a quartet of cells clinging tremulously together, progressing unsteadily materially toward the rim of my field of vision in the evolution of earthly life toward sponges, peripatus, ants and man.
We know of no ancestral form among the true Annelides, nor is it probable that it was derived from the intestinal worms. The only worm below the true Annelides that suggests any remote analogy to the insects is the singular and rare Peripatus, which lives on land in warm climates.
Sleep not in the dogmas of the Peripatus, Academy, or Porticus. Be a moralist of the mount, an Epictetus in the faith, and christianise thy notions.
In Peripatus we have a strange survivor of these primitive Annelid-Tracheates of many million years ago. The simple nature of its breathing apparatus suggests that the trachere were developed out of glands in the skin; just as the fish, when it came on land, probably developed lungs from its swimming bladders.
Word Of The Day