TISSUES OF THE BODY. 



199 



angular, and knotty. On being warmed, they assume, however, their 

 former smooth appearance once more. 



Again, we meet with peculiar appearances in those cells in which a part 

 of the solid fat of the contents has become crystalline (tig. 191, c). In 

 such, groups of needle-shaped crystals, either single, double, or in greater 

 number, are to be found. These were declared formerly, quite arbitrarily, 

 by microscopists, to be composed of inargarin or margaric acid. Such cells 

 have long been known. Eventually, the whole contents may be converted 

 into such a crystalline mass (K'6llik.er). 



Such cells are the result of the cooling' of the corpse, and are not found 

 in the warm living body. 



REMARKS. 1. Todd and Bovmianris Physiol. Anat., vol. i. p. 80. 2. Fat-cells 

 mounted in glycerin usually show these crystallisations. 



121. 



These normal cells just described i.e.) those surcharged with fat have 

 little instructive about them. There 

 can be but little doubt that here 

 also the oil globule is enveloped in 

 a thin coating of protoplasm with 

 a peripheral nucleus. This will be 

 easily understood after examination 

 of those cells, poor or almost entirely 

 deprived of fatty contents, the serum 

 cells of early observers (fig. 192, 

 2, b), small structures found in 

 emaciated subjects. Here we find 

 an abundant, probably watery, proto- 

 plasm in the place of the fat. Let 

 us examine such cells somewhat more 

 minutely. 



Instances are met with, in the 

 first place, in which a considerable 

 fat globule is separated from the 

 delicate outline of the envelope by 

 a thin interposed layer of fluid (1, 

 a, 6), in which the nucleus (c, d), 

 situated at the circumference, may 

 be discovered. The latter is smooth 

 in outline, and at times vesicular. 

 In such cases we not unfrequently 

 observe a darker yellowish tint than 

 usual in the fatty contents, which inten- 

 sifies the more the latter decreases in 

 quantity; so that adipose tissue which 

 has undergone this change strikes 

 even the unaided eye on account 

 of its yellowish-red appearance. When such fat-cells are crowded 

 together, they frequently give rise to an uncommonly delicate structure 

 resembling hyaline cartilage surcharged with fatty globules. 



Owing to the progressive disappearance of fat from these cells, we 

 not unfrequently find an oil globule decreasing more and more in 

 size (/). In others, this decreasing globule may become divided into 



192. Cells incompletely filled with fats. 



From the subcutaneous cellular tissue of 

 a lean human subject, in which the amount 

 of fatty contents is on the decrease, a, with 

 a large, 6, with a smaller oil globule ; c and 

 rf, the nuclei visible ; e, a cell with separate 

 globules : /, with a single small drop ; g. 

 almost free of fat ; and h, without fat and 

 with a globule of an albuminous substance 

 in the interior. 2. Cells of fatty tissue 

 from tlie neighbourhood of the kidney of 

 a sheep embryo, measuring 10 inches. 

 They are becoming filled more and more 

 with fat; a and 6, isolated cells without 

 the latter; r, a collection of the same; d-h, 

 cells with increasing deposit of fatty con- 

 tents. 



