from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Segmenting unequally; said of telolecithal ova with complete segmentation.
from the GNU version of the Collaborative International Dictionary of English
- adj. Segmenting unequally; -- said of telolecithal ova with complete segmentation.
from The Century Dictionary and Cyclopedia
- In embryology, a term applied to those holoblastic eggs which, by unequal segmentation of the vitellus (yolk), produce an amphigastrula (which see) in germinating.
Of the older dipnoi (Paladipneusta) we have now only one specimen, the remarkable Ceratodus of East Australia; its amphiblastic gastrulation has been recently explained by Richard Semon (cf. Chapter 2.21).
While the amphiblastic ova of the latter are small and develop like those of the amphibia, the cucumber-shaped ova of the hag are about an inch long, and form a discoid gastrula.
It was not until the beginning of the twentieth century that Bashford Dean made the important discovery in Japan that one of the oldest living fishes of the shark type (Cestracion japonicus) has the same total unequal segmentation as the amphiblastic plated fishes (ganoides).
All these amphiblastic vertebrates, Petromyzon and Cestracion,