It is really good to have the material brought in by Ingmar in “More Modes of Birth (1)” from the Vimalaprabhā Kālacakra commentary. This is a very important source for Book of Dzyan research. It is probably the only source that gives the correspondences of the four modes of birth with the five elements. The material nicely given from Vimalaprabhā 2.34 in Ingmar’s tables agrees with what was given in Vimalaprabhā 1.4. At 1.4 the correspondences are given a little more fully. Besides the egg-born from the element “air,” the womb-born from the element “fire,” and the sweat-born from the element “water,” it says that the upapāduka, here trees, etc. (the “stationary” of 2.34), are from the element “earth.” It then adds another kind of upapāduka, the great upapāduka (mahopapāduka), from the element ākāśa, “space” (here called rasa, “taste”). It does not say what these great upapāduka or self-produced beings are, but at 2.34 they are described as having the form of taste (rasa-rūpa), a term used here in Kālacakra for ākāśa. The Vimalaprabhā does briefly define upapāduka later, at 4.51, as instantaneous arising (yo jhaṭitaḥ sa upapādukotpādaḥ).
For readers who would like access to the romanized Sanskrit of the Vimalaprabhā passage at 1.4, along with an English translation, it can be found in “New Light on the Book of Dzyan,” in Symposium on H. P. Blavatsky’s Secret Doctrine: Proceedings (San Diego: Wizards Bookshelf, 1984), pp. 54-67; reprinted in Blavatsky’s Secret Books (1999), pp. 25-41. At the time that was written, I did not know about the further reference in 2.34 (nor, for that matter, did I remember it now until Ingmar brought it in).
Interestingly, the Vimalaprabhā at 1.4 gives the four modes of birth as tiryag-yoniś caturdhā, that is, as of animals. Similarly, at 2.34, it says bhūta-yoni (where the word had to fit the meter in the verse), the modes of birth of creatures or living beings, and gives examples only of insects, etc. There is no indication here in Kālacakra that these modes of birth would also apply to humans. It is only in the Buddhist Abhidharma that the four modes of birth are specifically said to also apply to humans.