The question as to the comparative structure and origin of the yolk nucleus involves several other problems:
1. Is the yolk nucleus a normal element of the egg cytoplasm, or is it associated with pathological states of the egg, or is it an artefact due to reagents?
2. Is there a necessary connection between one form and another such that one can be derived from the other?
3. Is it an amorphous chemical substance or does it possess anything suggesting permanence of structure?
4. Does it arise de novo or is it a modification of something similar existing in the cytoplasm of the oogonium?
5. Does it arise from chromatin eliminated from the germinal vesicle?
6. Is it due to cells entering the egg?
The answer to these questions will determine whether or not it is important
