Now as the vāsanās are of the nature of saṃskāras or impressions, they lie ingrained in the citta and nothing can prevent their being revived. The intervention of other births has no effect. For this reason, the vāsanās of a dog-life are at once revived in another dog-life, though between the first dog-life and the second dog-life, the individual may have passed through many other lives, as a man, a bull, etc., though the second dog-life may take place many hundreds of years after the first dog-life and in quite different countries. The difference between saṃskāras, impressions, and smṛti or memory is simply this that the former is the latent state whereas the latter is the manifested state; so we see that the memory and the impressions are identical in nature, so that whenever a saṃskāra is revived, it means nothing but the manifestation of the memory of the same experiences conserved in the saṃskāra in a latent state. Experiences, when they take place, keep their impressions in the mind, though thousands of other experiences, lapse of time, etc., may intervene. They are revived in one moment with the proper cause of their revival, and the other intervening experiences can in no way hinder this revival. So it is with the vāsanās, which are revived at once according to the particular fructification of the karmāśaya, in the form of a particular life, as a man, a dog, or anything else. It is now clear that the karmāśaya tending towards fructification is the cause of the manifestation of the vāsanās already existing in the mind in a latent form. Thus the Sūtra says:—“When two similar lives are separated by many births, long lapses of time and remoteness of space, even then for the purpose of the revival of the vāsanās, they may be regarded as immediately following each other, for the memories and impressions are the same” (_Yoga-sūtra_, IV. 9). The _Bhāshya_ says: “the vāsanā is like the memory (smṛti), and so there can be memory from the impressions of past lives separated by many lives and by remote tracts of country. From these memories the impressions (saṃskāras) are derived, and the memories are revived by manifestation of the karmāśayas, and though memories from past impressions may have many lives intervening, these interventions do not destroy the causal antecedence of those past lives” (IV. 9).