THE LEUCOCYTES IN ORGANIC FUNCTIONS. 673 



pressed the nuclear substance inwardly. The stages of this 

 compression are exemplified in Metchnikoff's plate, by Figs. 16 

 and 15, successively. In the former a single mass of liquid and 

 germs is seen to have indented the center of the nucleus on 

 one side, while in the second figure three cavities are shown 

 which have distorted it. (The nucleus is indicated by an n.) 

 In loth, however, the compression has exceeded the normal 

 boundaries of the limiting structure, and centrifugal bulging 

 has occurred at the expense of the pericellular protoplasm or 

 cytoplasm. So marked has this become in Fig. 14 that the 

 nucleus is not discernible. 



The identity of the mitoma as a system of canaliculi seems 

 to us shown in another way. We have found that the axis- 

 cylinders of nerves, 'neuroglia fibrils, etc., contained blood- 

 plasma. Such being the- case, if the fibers or "threads" in leuco- 

 cytes are likewise plasma channels, they must stain, as do the 

 former, when treated to various dyes. We have seen (pages 

 541 to 543) that methylene-blue, dissolved in salt solution and 

 injected into the vessels of a living animal, colored the axis- 

 cylinders blue, according to Ehrlich, and that this investigator 

 defined the conditions of nerve-structure essential to the 

 methylene-blue reaction as "oxygen saturation and alkalinity" 

 the very attributes of blood-plasma. Eeferring to the vari- 

 ous stains used by him, Gulland says: "In examining the baso- 

 phile cells I used almost entirely various methylene-blue solu- 

 tions," and, later on: "The basophile cells of the dog's intes- 

 tinal villi, when fixed with absolute alcohol and stained with 

 alcoholic methylene-blue, give exactly the same results, as to 

 mitoma and granules, as other basophiles." Evidently, as re- 

 gards the methylene-blue stain, nerve-fibrils and mitoma (our 

 canaliculi) are similar. Again, in addition to the plate we re- 

 produce, Gulland presents two colored plates in which the char- 

 acteristic affinity of each cell for stains appears; the six baso- 

 phile leucocytes stained with methylene-blue (normal) dis- 

 tinctly show that structures which stain most deeply is the 

 chromatic, i.e., the nuclear mitoma; then, more faintly, the 

 cellular mitoma. It seems clear that, as regards methylene-blue 

 stain at least, the conditions are similar to those of nerves as 

 far as the mitoma or canaliculi are concerned. 



