from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Alternative form of caenogenetic.
from the GNU version of the Collaborative International Dictionary of English
- adj. of or pertaining to cenogenesis. Opposite of
from The Century Dictionary and Cyclopedia
- Of or pertaining to cœnogensis.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. of or relating to cenogenesis
Sorry, no etymologies found.
On the other hand, this is certainly not the case with the following embryonic forms, which we must describe as cenogenetic processes: the formation of the yelk-sac, the allantois, the placenta, the amnion, the serolemma, and the chorion -- or, generally speaking, the various foetal membranes and the corresponding changes in the blood vessels.
In all other extent Vertebrates these fundamental processes have been more or less modified by adaptation to the conditions of embryonic development especially by changes in the food yolk; they exhibit various cenogenetic forms of the formations of the germlayers, and thus develop by means of a metagastrula.
It is worthy of note that the help of comparative anatomy is admittedly required in deciding what processes are palingenetic and what cenogenetic (p. 412).
This typical formation might be masked by cenogenetic modifications caused chiefly by the presence of yolk.
Gastræa theory (1875),  he had to work out a distinction between palingenetic and cenogenetic characters, of which much use was made by subsequent writers.
The cenogenetic phenomena, on the other hand, or the embryonic _variations_, cannot be traced to inheritance from a mature ancestor, but are due to the adaption of the embryo or the larva to certain conditions of its individual development (e.g. the amnion, the allantois, and the vitelline arteries in the embryos of the higher vertebrates).
Moreover, in the animals in which we do not find a real palingenetic blastula the defect is clearly due to cenogenetic causes, such as the formation of food-yelk and other embryonic adaptations.
When these coelom-embryos develop, not as a pair of hollow pouches, but as solid layers of cells (in the shape of a pair of mesodermal streaks) -- as happens in the higher vertebrates -- we have a secondary (cenogenetic) modification of the primary (palingenetic) structure; the two walls of the pouches, inner and outer, have been pressed together by the expansion of the large food-yelk.
The cenogenetic modifications of the latter are more appreciable the more food-yelk is stored up in the ovum.
These cenogenetic modifications seem to be so great that until twenty years ago these important processes were totally misunderstood.