have precisely similar relations to the cell, and both elevate the cell-membrane into a prominence at the points where they are attached. When one of these cells is pressed under the compressorium, the cell-membrane is at first remarkably expanded, and then tears to a very limited extent, allowing the fat to flow out. When the pressure is discontinued, it contracts again strongly. It has a minutely granulous aspect, is soft and very elastic, but not fibrous.
In close apposition, the cells become flattened against one another into polyhedral shapes, and, as Gurlt remarks, they then resemble vegetable cells in their appearance. We, however, may go further, and regard them as corresponding in signification also. In them the fat forms the cell-contents, as the pigment does in its cells, and the ethereal oil, &c. in those of plants. In its physiological signification of nutritive deposit it has more analogy with starch than with any other substance. I know not whether the nucleus is the part first formed in these cells, or not. Nuclei without any investing cells are found in the cranial cavity of the carp, lying with the adipose cells in the surrounding cytoblastema; these, however, may be nuclei of fibre-cells of areolar tissue. Sooner or later the nuclei become absorbed. They were still quite distinct in the adipose cells of the subcutaneous areolar tissue in the thigh of the before-mentioned rickety child twelve months old, whilst I could not detect any in the neck of a foetus at the seventh month. The absorption of the nucleus proceeds in one of two ways; either its external contour becomes gradually indistinct, some granulous substance merely being left in its place, which substance also disappears at a later period, or small fat-globules are formed both within the nucleus itself, and in its immediate proximity, which go on increasing in size, whilst the nucleus gradually disappears. The cell-membrane probably remains, even in the mature condition of the tissue, and Gurlt has made the very interesting observation, that in emaciated persons, the ordinary adipose cells are filled with serum.
c. The third kind of cells which occur in the areolar tissue of the foetus are round, for the most part extremely pale and transparent (pl. III, fig. 9.) They vary very much in size,.
