316. In forms of use belonging to the animal kingdom, a similar image of creation is found. For example, from a seed implanted in the womb or in an ovum, a body is formed, which is the last stage in its development, and when this matures it produces new seeds. This progression is similar to the progression in forms of use belonging to the plant kingdom. Seeds are its beginnings; the womb or egg is comparable to the earth; the state before birth is comparable to the state of a seed in the earth when it is taking root; and the state after birth to the time of reproduction is comparable to the sprouting of a tree to the state of its bearing fruit. It is apparent from this parallel that as there is a likeness of creation in the forms of plants, so there is a likeness of creation in the forms of animals-namely, that they exhibit a progression from their first constituents to their last, and from their last constituents to their first. [2] A similar image of creation exists in every particular found in the human being, for there is a similar progression of love through wisdom into useful endeavor, consequently a similar progression of will through the intellect into actions, and a similar progression of charity through faith into works. The will and intellect, or charity and faith, are the first constituents from which actions or works originate. Actions and works are the last constituents. From these last constituents a return is made through the delights of useful endeavors to their first constituents, which as we said are the will and intellect, or charity and faith. That a return is made through the delights of useful endeavors is clearly apparent from the delights perceived in actions and works that are connected with any love, in that they flow back to the first element of love from which they originated and thereby bring about conjunction. Delights perceived in actions and works are the delights that we call delights of useful endeavor. [3] A similar progression from their first constituents to their last, and from their last constituents to their first, exists in the most purely organic forms of the affections and thoughts in a person. In his brain these forms are starlike, called gray matter. Traveling out from these forms through the medullary substance through the neck into the body are fibers which continue on to the last constituents there, and which from the last constituents return to their first origins. The return of these fibers to their first origins takes place through the blood vessels. [4] Similar to this progression is the progression of all affections and thoughts, which are changes and variations in the states of these forms and substances. For the fibers traveling out from these forms or substances are comparatively like the atmospheres arising from the spiritual sun, which are the conveyers of heat and light; and actions produced by the body are comparatively like the productions produced through the atmospheres out of the earth, the delights of whose useful endeavors return to the origin from which they arose. Still, the existence in these forms of such a progression, and the presence in the progression of an image of creation, can with difficulty be comprehended with a full understanding of the matter, because the thousands and tens of thousands of forces operating in any action appear as one, and because the delights of useful endeavors do not produce in the thought any visible images, but only affect it without a clear perception of them. Concerning this subject, see what we have said and shown previously, as for example, that the uses of all things that have been created ascend by degrees of height to mankind, and through mankind to God the Creator from whom they originate (nos. 65-68); and that the end in creation finds expression in the lasts of it, which is for everything to return to the Creator and conjunction take place (nos. 167-172). But these matters will appear in a still clearer light in the next part, where we will take up the correspondence of the will and the intellect with the heart and the lungs.