In the first periods after conception, the fœtus is only a mucous mass, homogeneous in appearance, and in which the cellular texture seems almost exclusively to predominate. In fact, when the organs begin to be developed in this mass, the spaces that are left between them are filled with a substance which, exactly similar to that which before formed the whole of the body, can be considered as the residue of it, or rather perhaps it exists in a distinct manner, because it has not been penetrated with the peculiar nutritive substance, like that which forms the parenchyma of nutrition of the organs, which before this penetration resembled it precisely. This substance that lies between the organs, and which is the principle of the cellular texture, is the farther removed from a fluid state, as the period of labour approaches. First it is a true mucus, then a kind of glue, then the cellular texture begins to appear. This primitive state of the cellular organ, this appearance that it has at first, is owing to the great quantity of fluids that enter it at that period; it does not denote an inorganic existence; we can then compare it to the vitreous humour, which appears wholly fluid at first sight, because the transparency of its layers do not permit us to see them in the humour that enters its cells; make a puncture so as to evacuate this humour, and they become evident. Thus the cellular texture, extremely fine and even transparent in the first periods of life, is then concealed by the humour that fills it, and becomes more sensible as this humour diminishes with age. This phenomenon sometimes takes place in after life, in different serous infiltrations, those especially in which the infiltrated fluid has some viscidity. What is this humour that is so abundant in the cellular system, in the first months after conception? Is it albuminous like that which afterwards lubricates it? Probably it is; I should think, also, that it has much of the character of gelatine, a character which predominates, we know, in the animal humours at this period; I know of no experiment upon this point. Whatever the humour is, it is much more viscid and unctuous than it is afterwards; the touch is sufficient to convince us of this. It is its predominance, joined to the delicacy of the cellular layers, that, in the first months, makes every attempt to render the fœtus emphysematous, by blowing air under the skin, almost absolutely useless.