OF THE CHANGES IN A SINGLE FAT VESICLE. 133 



are concerned in tlie production of fat. These are, 

 indeed, at a very early period in contact with the 

 external surface of the vascular wall. It certainly is 

 not possible to determine by any appearance mani- 

 fested by the numerous bioplasts in the immediate 

 neighbourhood of the vessels, which of them, are to 

 take part in the development of new capillaries, and 

 which are to become connective tissue or fat. The 

 capillaries themselves multiply as the adipose vesicles 

 grow, and the vascular network increases as in other 

 situations, by the extension of bioplasts in a loop-like 

 form from the capillaries already existing. 



188. Of the changes in a single fat vesicle. — The 

 changes taking place in the development of an indi- 

 vidual adipose vesicle may be thus described. At first 

 all that is to be discerned is the small oval or spherical 

 mass of bioplasm or living matter, which is perfectly 

 naked, that is, it is entirely destitute of a cell wall. 

 This little bioplast usually exihibits one or more new 

 centres of development (nuclei) embedded in it. The 

 formation of the fatty matter occurs in this way : — 

 in the very substance of the bioplasm, but always out- 

 side and awFiy from the new centre or nucleus, a little 

 oil globule makes its appearace. It results from 

 changes in the living matter itself. A portion of the 

 bioplasm dies, and among the substances resulting 

 from its death is fatty matter, which being insoluble 

 remains, while the soluble substances which are also 

 formed, are carried away in the blood. Starch globules 

 and other secondary deposits formed in the interior of 

 elementary parts are produced in the same manner by 

 the death of the bioplasm (§§ 127, 128). The fatty 

 matter does not come from the blood as fat, and de- 

 posit itself in the cell, nor is it formed by the collec- 

 tion and aggregation of excessively minute grantiles, 

 which traverse the vascular walls suspended in serum, 

 as some have taught ; nor is it precipitated from the 

 nutrient fluid after the manner of crystals. But it 



