An appeal made by Muller for observations on the development of the Caeciliae, and of those Amphibia which retain gills or gill-clefts throughout life, has unfortunately yielded no fruits.
In the Hunterian lectures delivered at the Royal College of Surgeons in 1863, Huxley divided the Vertebrata into Mammals, Sauroids and Ichthyoids, the latter division containing the Amphibia and Pisces.
The bony skull in man and all the other amniotes is more highly differentiated and modified than that of the lower vertebrates, the amphibia and fishes.
Although this unequal segmentation of the cyclostoma, ganoids, and amphibia seems at first sight to differ from the original equal segmentation (for instance, in the monoxenia, Figure 1.
The formation of a large food-yelk followed again in the stem-forms of the amniotes, the protamniotes or proreptilia, descended from the amphibia (Figure 1.
When we consider still earlier stages of development, we are unable to discover any essential difference in bodily structure between the embryos of these higher vertebrates and those of the lower, the amphibia and fishes.
The structure of the chorda also shows the same features in these coelomula-embryos of the amphibia (Figure 1.
This is clearly shown by the ova of the amphibia and cyclostoma, which explain the transition from the yelk-less ova of the amphioxus to the large yelk-filled ova of the reptiles and birds.
This reduction becomes easier if, after considering the gastrulation of the tailless amphibia (frogs and toads), we glance for a moment at that of the tailed amphibia, the salamanders.
The colouring of the eggs of the amphibia is caused by the accumulation of dark-colouring matter at the animal pole of the ovum.
It was first observed in the ovum of the amphibia by Rusconi, and so called the Rusconian cavity.
Later it approaches very closely, at one period, to the anatomic structure of the lancelet, afterwards to that of a fish, and again to the typical build of the amphibia and mammals.
It is a fair inference that the tadpole stage in the life history of the frog represents a stage in the evolution of its kind,--that the Amphibia are derived from fishlike ancestral forms.
This inference is amply confirmed in the geological record; fishes appeared before Amphibia and were connected with them by transitional forms.
An annotated checklist and key to the Amphibia of Mexico.
A new order of fishlike Amphibia from the Pennsylvanian of Kansas.
In Amphibia the specialisation of the opening appears to have gone so far that it no longer has any relation to the head-kidney, and even develops after the atrophy of the head-kidney.
The development of the head-kidney in Amphibia has been fully elucidated by the researches of W.
In the Cyclostomata and Amphibia the pronephros is a purely larval organ, which either disappears or ceases to be functionally active in the adult state.
In Petromyzon andAmphibia the head-kidney atrophies.
In Amphibia the single late formed and radiately striated (Waldeyer) membrane would appear to be a zona radiata.
The head-kidney is developed from the anterior end of this canal, the opening of which remains in Teleostei single and closes early in embryonic life, but becomes in Amphibia divided into two, three, or four openings.
If this homology is admitted, the identity in position of this organ in Aves and Amphibia necessarily follows.
This process appears partly to have taken place in Elasmobranchii, and still more in Amphibia; the Amphibia offering in this respect a less primitive condition than Elasmobranchii; while in Aves it has been carried even further.
This is not the place to enter into the obscure question as to how far the ribs of the Amphibia and Amniota are homologous with those of Fishes.
In Amphibiaand Teleostei it takes place upon the same type, viz.
In Amphibia this is a new formation, but in Elasmobranchii it is the original opening of the segmental duct.
With reference to the first of these points the facts of the case are the following:-- In Amphibia the permanent opening of the Muellerian duct is formed as an independent opening after the atrophy of the head-kidney.
If this account is correct, Petromyzon presents a type intermediate between Amphibia and Elasmobranchii.
Their ancestors, the amphibia of the Carboniferous period, still lived and breathed in the water, like their earlier predecessors, the fishes.
In the case of these older and lower vertebrates that lived in the water, the embryonic development had the palingenetic character in a still higher degree, as is the case in most of the fishes and amphibia of the present day.
The most important branch of the vertebrates, the mammals, were developed later (during the triassic period) from the lower amphibia and the reptilia.
Lydekker, Catalogue of the Fossil Reptilia andAmphibia in the British Museum, part iv.
Gadow, "On the Evolution of the Vertebral Column of Amphibiaand Amniota," Phil.
The helminths parasitic in the Amphibia and Reptilia of Houston, Texas and vicinity.
The Anurous Amphibia have prepared us to recognise this too as a case of secondary adult (post-embryonic) metamorphosis.
When the tadpole has four limbs and a long tail it has already reached the point at which the more primitive Amphibia (Menopoma, Proteus, &c.
Which of the amphibia in this study are fish-like in character?
Do you think these fish-like amphibia are of a lower or higher type than the others?
The general absence of theamphibia from arid regions.
The fin of a fish is used as an organ of locomotion in water; from some such organ have evolved the walking limbs of amphibiaand reptiles, constructed for progression upon land.
Following the fishes, the amphibia arose during the coal age or Carboniferous, usurping the proud position of the lower vertebrate class.
Only a few of the countless details have been mentioned which demonstrate the resemblance of the successive stages first to fishes, and later to amphibia and reptiles.
In their whole organisation even the actual Amphibia seem to be an instructive transitional group.
The lower Amphibia approach very closely to the Dipneusta in their whole organisation, live mainly in the water, and breathe by gills; but the higher Amphibia are just as close to the Amniotes, live mainly on land, and breathe by lungs.
In theAmphibia the partition between the two auricles is complete.
We have several fossil remains of five-toed Amphibia from this period.
These amphibia increase in variety in the Permian epoch.
The great interest of the natural history of the Amphibia consists especially in their intermediate position between the lower and higher Vertebrates.
It is probable that the Amphibia were evolved even earlier--during the Devonian period--from the Dipneusta.
Hence we find, as a matter of fact, that the brain is much more developed in the higher Amphibia than in the fishes, the Dipneusta, and the lower Amphibia.
There were plenty of highly-developed (and sometimes large) Amphibia during the Carboniferous period; but the earliest reptiles are only found in the Permian period.
These six families are then sub-divided into many smaller families, and the Amphibia are grouped by themselves instead of being included among the Carnivora—although they are flesh eaters, and this seems to be their proper place.
Owing to this precaution of nature theAmphibia can wander freely about in the depths of the ocean in search of their food.
As their members are badly fitted for locomotion on land, the Amphibia only leave the water when they want to sleep, or while their babies are very young, and feed on the mother’s milk.
The Amphibia do not live in very warm regions, and they increase more and more in number in proportion as one advances towards the poles.
The inertness of the Amphibia is, on the other hand, accompanied by relatively great length of life.
The most active birds have very long lives, as will be shown later on: they live as long as and sometimes longer than the majority of Amphibia which reach the same size.
The arrangement of these bones, peculiar and often complicated, but everywhere essentially the same in all the Tetrapoda, is a striking evidence that man is a descendant from the oldest pentadactyle Amphibia of the Carboniferous period.
Be it remembered that all the recent Amphibia still undergo the same metamorphosis during their ontogenetic development.
Selachians and Ganoids existed in the Silurian times, Dipnoi in the Devonian, Amphibia in the Carboniferous, Reptilia in the Permian, Mammalia in the Trias.
Defn: A division of Amphibia including the Salamanders and allied groups; the Urodela.
Defn: A grand division of the Vertebrata, including the Amphibia and Fishes.
The lens of the eye of certain Amphibia is formed of their skin in response to a formative stimulus proceeding from the so-called primary optic vesicle.
The amphibia of the frog species, which lie concealed in silent repose during the day, raise, after sunset, their far-sounding voices.
Multitudes of venomous amphibia are hatched in the half-putrescent vegetable matter, and he who inadvertently steps on one of these animals may consider himself uncommonly fortunate if he can effect his retreat without being wounded.
The amphibia on the Peruvian coast are proportionally much better represented than the two foregoing classes.
Of the amphibia in the principal forests of Peru, only the great fresh-water tortoise (Hydraspis expansa, Fitz.
Among the few amphibia found in these regions one is particularly remarkable.
Among the amphibiain Callao, the iguana and land agama are numerous.
A Catalogue of the Species of Reptiles and Amphibiahitherto described as inhabiting Australia, with a description of some New Species from Western Australia, and some remarks on their geographical distribution, by John Edward Gray, F.
In the Amphibia it is found close to the articulation of the mandible.
In the Amphibia the thyroid forms numerous vesicles close to the anterior end of the pericardium.
In the Amphibia the glands are sunk into the surface of the kidney.
The helminths parasitic in the Amphibia and Reptilia of Houston, Texas, and vicinity.
Notes on Amphibia and Lacertilia collected at Weymouth, N.
The vertebrates consist of forms of fish, amphibia and reptiles, and the Permian rocks are the earliest strata in which the remains of true Reptilia are known to occur with certainty.
The chief variation is in the amount of protein present, which attains its maximum concentration in birds and mammals, while in reptiles, amphibia and fishes it is much less.
The coloured corpuscles of amphibia as well as of nearly all vertebrates below mammals are biconvex and elliptical.
In reptiles and amphibia the red corpuscles are also nucleated, but the stroma portion containing the haemoglobin is arranged in a thickened annular part encircling the nucleus.
The small hare (Lepus Americanus) and the grey squirrel were almost the only quadrupeds we saw in these woods; but of the class of amphibia there were many kinds.
There are but few species of amphibia in the country about Harmony.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "amphibia" in a variety of sentences. We hope that you will now be able to make sentences using this word.
