QUANTITATIVE HEMATOLOGIC DATA 605 



Jacobsen and Plum {1398-H00,21o5-2158) have shown that the velocity of 

 this process depends on the presence of a reticulocyte-ripening principle in 

 the plasma. The nature of this principle is not yet fully elucidated. Liver 

 and particularly stomach extracts contain a heat-labile substance, probably 

 of purine character, which is activated by tyrosine and (more strongly) by 

 hallachrome, the latter being assumed to be formed from tyrosine by tyro- 

 sina.se, probably in the erythrocyte. The gastric factor appears to be com- 

 bined with the activator in the reticuloendothelial system. 



The appearance of hemoglobin in the red cell has been studied histologically 

 by observing the change of the basophilic material of the cytoplasm into 

 eosinophilic (orthochromatic) material. Some workers assume that the 

 chromatin of the cell nucleus develops into hemoglobin (1796,2072,2250). 

 This hypothesis needs modification in the light of modern knowledge on the 

 role of nucleoproteins in protein .synthesis.* In the embryo or when the 

 megaloblastic red cell formation is found pathologically, hemoglobin appears 

 early in the development of the cell, but in the normoblastic development in 

 the normal adult it appears only in the later stages when the nucleus becomes 

 pyknotic. Hemoglobin formation appears to be completed before the nucleus 

 is extruded. Under conditions of hastened hemopoiesis, hemoglobinization 

 may be almost completed in the nucleated and still dividing cells of the 

 adult bone marrow {1386). 



2.2. Quantitative Hematologic Data 



In adult men the number of erythrocytes per mm.^ is about 5.4 

 million, in women about 4.8 million. The diameter of the normal 

 mature erythrocyte is 7-8 ^i, its average thickness 2 n, its mean cor- 

 puscular volume 75-95 n^. There are roughlj- 25 X 10^- erythrocytes 

 in the circulating blood. According to modern estimations, the aver- 

 age hemoglobin content of the blood of adult men is 15.5 to 16 g. 

 per 100 ml. blood. For women a figure of 14.0 to 14.5 g. per 100 ml. 

 can be considered normal; frequently, however, smaller values for 

 hemoglobin and erythrocyte count are found, since the larger physi- 

 ologic demands for replacement of iron, due to blood loss in men- 

 struation and pregnancy, are not completely met. By iron therapy, 

 Widdowson and McCance {3069) were able to raise the hemoglobin 

 content of the blood of women from 1.3.8 to 15.3 g. per 100 ml., while 

 that of men remained unaltered. There is a definite need to dis- 

 tinguish between the average level of "healthy" women and a 

 "normal" level, which should be obtained from individuals living 

 under optimal conditions {cf. 6^6). This is a matter of social impor- 

 tance. The hemoglobin content of the blood of other omnivorous or 



* B. Thorell (2799a) has recently shown that hemoglobin — at least its prosthetic 

 group — is synthesized, after the protein synthesis from cytoplasmic ribose poly- 

 nucleotides has been practically completed. 



