688 INTERNAL SECRETIONS AND PRESERVATION OF LIFE. 



Our purpose being to ascertain the physiological functions 

 of the various types, Ehrlich's four classes, by affording def- 

 inite microchemical limits, will probably prove more useful 

 than the simplified groupings that other histologists have in- 

 troduced, and which, by reducing the number of divisions, have 

 tended to efface landmarks that can serve as clues for research. 

 We will preserve, therefore, Ehrlich's classification, and try to 

 ascertain whether the various types of cell do not differ phys- 

 iologically from one another as they do histologically. 



LYMPHOCYTES AND HYALINE CELLS. The first cell of 

 the Ehrlich series, the lymphocyte, seems fully entitled to the 

 position accorded it- by histologists in general: that of a leu- 

 cocyte in process of development. The cellular substance is 

 devoid of canaliculi (or net-work of mitoma) and of granules, 

 although the nucleus itself is supplied with both, and is evi- 

 dently functionally active. Lymphocytes are considerably 

 smaller (6 to 6.5 fi ) than leucocytes, and represent less than 

 one-fourth of the total number of these cells. They are devoid 

 of amoeboid motion. Hyaline cells have been classed in the 

 same category, the cell-body being likewise free from granules, 

 as shown in Gulland's plate, Fig. 1. Both may become active, 

 however, before complete maturity is reached. 



NEUTEOPHILE LEUCOCYTES. These are extremely impor- 

 tant members of the leucocyte family, for they represent fully 

 three-fourths of the white cells of the blood, and constitute 

 MetchnikofFs main group of phagocytes. They are termed 

 "neutrophile" by Ebrlich because their granulations stain with 

 both acid and basic dyes. Their reaction to acid dyes is very 

 much less intense, however, than is the case with purely acido- 

 phile cells, according to Kanthack and Hardy. Their gran- 

 ules are small as compared to those of other acidophile cells. 

 Though termed "polynuclear" leucocytes by Metchnikoff, the 

 masses thought to represent as many nuclei, are united by 

 thin bridges, thus constituting a single nucleus. Especially 

 is this likely since the only other type of cell deemed phago- 

 cytic by Metchnikoff is a mononuclear cell. Gulland contends 

 that no shape of nucleus is invariably associated with granules 

 of a special kind. It seems evident, therefore, that the phago- 

 cytic cells are only distinguishable by their affinity for alkaline 



