Table 5. — Classification of individual cells into lymphocytes and m onocytes ' 



Figure 



Cell 

 type 2 



Characteristic 



Cell 

 size 



+ 



+ 

 + 



+ 



+ 

 + 



Cell 

 shape 



+ 

 + 



+ 

 + 



+ 



+ 

 + 



+ 

 + 



+ 

 + 



Nuclear 

 position 



+ 

 + 

 + 

 + 

 + 

 + 



Nucleo- 



cytoso- 



III a 1 



ratio 



4- 

 + 



+ 



+ 

 + 



+ 



Cyto- 

 plasmic 

 struc- 

 ture 



+ 



+ 

 + 

 + 



Hof and 

 orange- 

 staining 

 spheres 



+ 

 + 



+ 

 + 

 + 

 + 



Specific 



cell 

 inclu- 

 sions 



I 



+ 



Nuclear 

 shape 



+ 



+ 



+ 



+ 

 + 



+ 



Nuclear 

 struc- 

 ture 



+ 

 + 



+ 



+ 



+ 



+ 

 + 



+ 

 + 



Cell 

 division 



(^rn(-iusi<jn 



Lynijjho- 

 cyle. 



Lm,i|.1i„- 

 IV Ic. 



Monocyte 

 Monocvle 

 MoiKicyle 

 Monocyte 



' See l;il.le 3. p. M. 



the cells lack a sufficient luiniher of cell features 

 by which differentiation can be followed. In 

 contrast, erythrocytes have hemoglobin; granu- 

 locytes and thrombocytes their various types of 

 specific granules. All these aids are lacking in 

 lymphocytes and monocytes. One must resort 

 to less reliable criteria such as lobulations, nu- 

 clear structure, and cytoplasmic texture and 

 colo)-. Three cells in the process of monocyto- 

 genesis have been shown in the spleen of a chick 

 35 days of age (fig. 331, 16-19). The imma- 

 ture cells have lobulated cytosomes with a uni- 

 form basophilic granulation and nuclei with 

 small clumps of chromatin, which are generally 

 uniformly scattered. The immature monocytes 

 of figures 139-144, found in the circulating 

 blood, have two types of nuclei — those with a 

 fine reticulum in which the chromatin stains a 

 pale purple color, and those in which the nucleus 

 takes an overall magenta color, including the 

 nucleoplasm. None of the cells in the first row 

 (figs. 139-142) came from the liirds that gave 

 figures 143-145; therefore, the difference in col- 

 oration may be due either to technic or to the bird, 

 and we should 

 phasizing this difference. 



Two early immature cells have been drawn 

 (figs. 139 and 140) but these are seen very rarely 

 in circulating blood; they may be found in blood 

 dyscrasias. The fine, highly dispersed pattern 

 of nuclear chromatin and the few remaining mito- 



liroljaldy guard against overeni- 



- L = lyniph<icytt!; M^inonocyle. 



chondrial spaces in the cytosome all indicate im- 

 maturity, and lobulation when combined with the 

 nuclear pattern, points to the same thing. Young 

 ]irimary erythroblasts in the circulating blood of 

 the 48-hour chick embryo are another example of 

 cells showing lobulations as an indication of their 

 immaturity. The azurophilic granules in the 

 cytosome of figure 140 aid in identifying it as a 

 monocyte, and the lobulation and nuclear pat- 

 tern identify it as a young cell. A few of these 

 granules take a magenta stain like the nucleus 

 and the specific granules of lymphocytes; a pair 

 of them, along the lower edge of the nucleus, ac- 

 tually appear to be connected with the nuclear 

 mendjrane by delicate strands. If it could he es- 

 tablished that magenta bodies actually arise as 

 extruded nuclear substance, it would go far to- 

 ward establishing that the usual type of azuro- 

 philic material of the monocyte, and the magenta 

 bodies found in a few monocytes and in many 

 abnormal and reactive lymphocytes, are not the 

 same. 



The amoeboid cell (fig. 143) is also a young 

 monocyte but it shows more extensive vacuoliza- 

 tion of the cytoplasm than figures 139 and 140. 

 In some cells, blebs project that appear to be 

 |)inrhing off. Later immature monocytes are il- 

 lustrated in figures 141, 142, and 144. Some 

 blebs are still present, the nucleus may be round 

 or nearly so, and a clear Hof has appeared. 



71 



