The following diagram shows the above details at a glance:*
The manifestation of the electron, the most finite gross form, or the first drop-bubble, is the beginning of the organic evolution that terminates in the human form. With the manifestation of this most finite drop-bubble, Atman, the drop, begins to know** the universe — nothingness most finitely. This experiencing of the universe by the Atman or soul through the electron is almost imperceptible and negligible; yet this minutest "knowing" or consciousness creates sanskaras — A'mal — Impressions, which cause the drop — Atman to leave the bubble — form. When the drop leaves the bubble, the sanskaras do not leave the Atman but remain about it, and again cause the Atman to take a bigger bubble or body. Through this second form, the Atman knows the universe more, as the angle of vision or the consciousness of knowing increases with the increase in the form. And with the increase in this consciousness, the sanskaras also increase and cause the drop to assume a yet bigger form when the second one falls off. And in this way, the evolution of drop-bubbles goes on for ages till, after countless changes of bubbles, the Atman gets the human form.
But the evolution is not of the drop (Atman) but of the bubble (body or form). The Atman remains the same Indivisible and Infinite Ocean from the beginning till the end of form evolution. But with the organic evolution, or advancement of the bubbles, the knowing or consciousness of ignorance — universe increases step by step. This consciousness on the part of the Atman is called chaitanya. This chaitanya becomes Jiv — individual in the human form. It is in the human form only that the Jivatman can realize the Paramatman, because with the Atman being infinite, the consciousness must also be infinite: and the consciousness is infinite only in the human form. Therefore the human form is the end of organic evolution.
The eight million four hundred thousands of bubbles or forms which the Atman is proverbially said to pass through are as*** the chief forms or the genera, each of which has its numberless species; and the Atman has to pass through all of them before it can incarnate in the human form. Yet, strictly speaking, there is only one form, viz., the human form, because, it is latent in all the previous forms including the electron. In other words, the different forms in the mineral, vegetable and animal kingdoms are nothing but the human form in its latent state which becomes completely manifested gradually as a human being in a human body.
*In Volume 3 Number 1 Page 37 the diagram reads "Seven Divisions Of The Subtle World. This special edition was printed later. A few meaningful words are different throughout it.
Also, in this edition, same diagram, they have included the words "FIGURE 6 DIVISION OF WORLDS." This is not written under the diagram in V. 3 N. 1 P. 37
** Volume 3 Number 1 Page 37 has an equal sign (=) after "begins knowing the universe = nothingness most finitely. Here it says "begins to know the universe—nothingness most finitely.
The next two paragraphs in Volume 3 Number 1 Pages 37 and 38 have many equal signs which changes the meaning where there are dashes in this edition.
***ERRATA: "as" is not there in the original edition Volume 3 Number 1 Page 38
all footnotes added here by webmaster-JK-2006