In biology, a parent of any kind; a stock: with reference to morphological considerations.(noun)
The Century Dictionary (Public Domain)
Use "parent-form" in a sentence
"As a consequence of this the embryo, even when the parent-form undergoes a great amount of modification, is left only slightly modified; and the embryos of widely-different animals which are descended from a common progenitor remain in many important respects like each other and their common progenitor."
"At present I should prefer any mad hypothesis, such as that every disintegrated molecule of the lowest forms can reproduce the parent-form, and that the molecules are universally distributed, and that they do not lose their vital power until heated to such a temperature that they decompose like dead organic particles."
"In either of these cases, the young or embryo will closely resemble the mature parent-form, as we have seen with the short-faced tumbler."