The corn snake yolk sac becomes a solid tissue filled with blood vessels and yolk-rich endodermal cells.

@article{Elinson2014TheCS,
  title={The corn snake yolk sac becomes a solid tissue filled with blood vessels and yolk-rich endodermal cells.},
  author={Richard P. Elinson and James R Stewart},
  journal={Biology letters},
  year={2014},
  volume={10 1},
  pages={20130870}
}
The amniote egg was a key innovation in vertebrate evolution because it supports an independent existence in terrestrial environments. The egg is provisioned with yolk, and development depends on the yolk sac for the mobilization of nutrients. We have examined the yolk sac of the corn snake Pantherophis guttatus by the dissection of living eggs. In contrast… CONTINUE READING