Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: August 19, 2024
An instance of the latter may be observed in the wingless female of the canker worm, so different from the winged male; this difference is created after the larval stage, for the caterpillars of both sexes are the same, so far as we know. So with numerous other examples among the moths.
A strong reaction set in during the latter part of the nineteenth century, when attention was directed to the anachronisms of the embryonic record and to the alterations that are the results of larval or embryonic adaptation as short cuts in development.
The third larval form only a few live to reach. This is of the usual long, oval form of the larvæ of the ichneumons, and the body has thirteen segments exclusive of the head. The muscular system has greatly developed and the larva is much more lively in its motions than before. The new organs that develop are the air tubes and fat bodies.
As we rise higher in the animal kingdom the characteristics of the successive higher groups are more and more slow of attainment and difficult of realization, just because of their grander possibilities. And this is true and important above all in the case of man. His possibilities are beyond our powers of conception, for, if you will, man is yet only larval man.
In most cases of infection the presence of these filariæ in the blood seems to cause no inconvenience to the host. They are probably never injurious in the larval stage, that is, in the stage in which they are found in the peripheral circulation. In many cases, however, the presence of the sexual forms in the lymphatics may cause serious complications.
Here, as with the ants, this thing has become a normal condition of the race, and the whole of such eplacement as is necessary falls upon this special and by no means numerous class of matrons, the mothers of the moon-world, large and stately beings beautifully fitted to bear the larval Selenite.
This last gives us the clew to our spelling pollwiggle, which, reversed and interpreted in a modern way, is wigglehead, a most appropriate name for these lively little black fellows. Tadpole is somewhat similar; toad-pole, or toad's-head, also very apt when we think of these small-bodied larval forms.
To keep out the light, which would disturb my insects destined to spend their larval life in complete darkness, I cover the tube with a thick paper sheath, easy to remove and replace when the time comes for observation. Lastly, the tubes thus prepared and containing either Osmiae or other bramble-dwellers are hung vertically, with the opening at the top, in a snug corner of my study.
These quit the egg with an unsegmented ovate body, a median frontal eye, and three pairs of natatory feet, of which the anterior are simple, and the other two biramose in fact, in the larval form, so common among the lower Crustacea, to which O.F. Muller gave the name of Nauplius.
They retained the evidence of their close relationship with the Devonian fishes in their cold blood, their gills and aquatic habit during their larval stage, their teeth with dentine infolded like those of the Devonian ganoids but still more intricately, and their biconcave vertebrae which never completely ossified.
Word Of The Day
Others Looking