CHAPTER 2 



Circiilatino Blood of the Hatched Chicken 



ERYTHROCYTES 



Normal mature erythrocytes (figs. 4—8) 



The "typical" erythrocyte of birds has often 

 l)een described as an oval cell with an oval nu- 

 cleus (Goodall, 1909; Foot, 1913; Magath and 

 Higgins, 1934; and many others). Forkner 

 (1929) has described in detail its appearance 

 in vital stained preparations. The nucleus is 

 not quite concentric with the contour of the cell; 

 there is a wider margin at the poles of the cell 

 than at the sides. The cytoplasm takes an orange 

 pink color with Wright's stain and with May- 

 Griinwald Giemsa gives a distinctly more red- 

 dish color. The nucleus stains intensely but re- 

 veals a pattern of chromatin clumps more or less 

 uniforndy distributed. If tlie nucleus has an 

 oval shape, there are no massive chromatin 

 clumps. If the nucleus is contracted to an elon- 

 gated rod-shaped structure, dense clumps of 

 chromatin are usually present. A nucleolus is 

 absent. 



Low-power views are presented in figures 2 

 and 3. The slide from which figure 2 was made 

 came from the flock of Single Comb Wliite Leg- 

 liorn chickens maintained at this Laboratory, 

 and figure 3 was drawn from a set of 25 slides 

 obtained from the same breed at another location, 

 which for convenience has been designated as 

 Laboratory No. 2. Thus, even in these two 

 samples, difl:erences can be observed and prob- 

 ably could be extended if a careful study were 

 made of blood from many sources. 



A typical cell is shown in figure 4. It was 

 necessary to do considerable searching to find 

 this "typical" cell. Examples are shown also 

 in figures 2, 7 and 3, 7. All the other cells de- 

 viate from it in shape of nucleus or cytosome or 

 both. The cells may be too round or too elon- 

 gate or irregular (fig. 3, 5) . The nuclei may be 

 too large or too small for the cytosome (figs. 2, 

 10 and 3, 10) ; the long axis of the nuclei may 

 not coincide with those of the cells that contain 



them, or they may be eccentrically placed (figs. 2, 

 9 and 3, 9) ; the nuclei may not be in the center 

 of the cells and may be blunt at one end and 

 pointed at the other. Most conspicuous of all are 

 the indentations (figs. 2, 11, 12 and 3, 11, 12), 

 constrictions (fig. 2, 13), and protrusions (figs. 

 2, 14 and 3, 14). Even duplications of the nu- 

 clei (figs. 7, 8, and 29) may be found. As far 

 as can be determined, these are all normal cells 

 and in spite of their multiplicity of shape they 

 are all instantly recognizable as mature erythro- 

 cytes, because the hemoglobin gives to the cyto- 

 some a strong affinity for acid dyes and a nearly 

 homogeneous texture. In some cases a narrow 

 rim of cytosome around tlie nucleus stains lighter 

 than the more peripheral part, but this is prob- 

 ably an artifact that developed when the cell 

 was flattened in the process of making the smear. 

 This perimiclear space is shown in figure 2 but 

 not ni figure 3. The clear space, as suggested, 

 may arise as an artifact but its occurrence in one 

 smear and not in another may be worthy of fur- 

 ther study. A perinuclear space appears in all 

 types of Idood cells, except the heterophil, when 

 the smear has lieen fixed in Petrunkevitch No. 2, 

 and stained in May-Griinwald Giemsa (figs. 

 198-202, 215, and 221). Following this tech- 

 nic the nucleus of the erythrocyte appears to be 

 almost a solid chromatin mass. 



Suggestions concerning the origin of multipo- 

 lar and giant erythrocytes and leukocytes in man 

 have been given by Schwarz (1946). He be- 

 lieves these conditions can be traced back to 

 multinuclear conditions in the immature stages. 

 Certain types of variability have significance. 

 Among the 25 blood smears received from Lab- 

 oratory No. 2 there were several in which the 

 nuclei of the erythrocytes were longer and nar- 

 rower (figs. 3, 8, and 5) than any found in smears 

 from our flock. Also, the chromatin was more 

 condensed and more heavily stained. The sig- 

 nificance is not known but the same type of eryth- 

 rocyte has been observed in some of the smears 



17 



