CHANGES OF THE RED AND WHITE BLOOD-CORPUSCLES. 23 



fluid from the tissues. Menstruation shows us that a moderate loss of red cor- 

 puscles is replaced within twenty-eight days. When a large amount of blood is 

 lost, so that all the vital processes are lowered, the time may be extended to five 

 weeks. In acute fevers, as the temperature increases, the number of red corpuscles 

 diminishes, while the white corpuscles increase in number (Kiegel & Boeckmann). 



(2.) Diminished production of new red corpuscles causes a decrease, since 

 blood-corpuscles are continually being used up. In chlorotic girls there seems to 

 be a congenital weakness in the blood-forming and blood-propelling apparatus, the 

 cause of which is to be sought for in some faulty condition of the rneso-blast. In 

 them the heart and the blood-vessels are small, and the absolute mimber of cor- 

 puscles may be diminished one-half, although the relative number may be retained, 

 while in the corpuscles themselves the haemoglobin is diminished almost one-third 

 (Duncan, Quincke) ; but it rises again after the administration of iron (Hayem). 

 The administration of iron increases the amount of haemoglobin in the blood 

 (Scherpf). The amount of iron in the blood maybe diminished one-half. [The 

 action of iron in anaemic persons has been known since the time of Sydenham. 

 Hayem also finds that in certain forms of anaemia there is considerable variation 

 in the size of the red corpuscles, and that in chronic anemia the mean diameter 

 of the corpuscles is always less than normal (7 M to 6 M). There is, moreover, a 

 persistent alteration in the volume, colouring power, and consistence of the cor- 

 puscles, consequently a want of accord between the number of the corpuscles and 

 their colouring power i.e., the amount of haemoglobin which they contain, as was 

 pointed out by Johaiui Duncan.] In so-called pernicious anwmia, in which the 

 continued decrease in the red corpuscles may ultimately produce death, there is 

 undoubtedly a severe affection of the blood-forming apparatus. The corpuscles 

 assume many abnormal and bizarre forms (microcytes), often being oval or tailed, 

 irregularly shaped, aud sometimes very pale ; while numerous cells containing 

 blood-corpuscles are found in the marrow of bone (Riess). Curiously enough in 

 this disease, although the red blood-corpuscles are diminished in number, some 

 may be larger and contain more hemoglobin than do normal corpuscles (Laache). 

 The number of coloured corpuscles is also diminished in chronic poisoning by lead 

 or miasmata, and also by the poison of syphilis. 



(3.) Abnormal forms of the red corpuscles have been observe! after severe 

 bums (Lesser) ; the corpuscles are much smaller, and under the influence of the 

 heat, particles seem to be detached from them just as can be seen happening under 

 the microscope as the effect of heat (Wertheim). Disintegration of the, corpuscles 

 into fine droplets has been observed in various diseases, as in severe malarial 

 fevers. The dark granules of a pigment closely related to haeinatin are derived from 

 the granules arising from the disintegration of the blood-corpuscles, and these 

 particles float in the blood (Melancemia). They are partly absorbed by the colour- 

 less corpuscles, but they are also deposited in the spleen, liver, brain, and bone- 

 marrow (Arnstein). Sometimes the red corpuscles are abnormally soft, and 

 readily yield to pressure. 



The white corpuscles are enormously increased in number in Leukaemia 

 (J. H. Bennett and Virchow) ; sometimes even to the extent of the red corpuscles. 

 In some cases the blood looks as if it were mixed with milk. The colourless cor- 

 puscles seem to be formed chiefly in bone-marrow (Neumann), but also in the 

 spleen and lymphatic glands. 



11. Chemical Constituents of the Red 

 Blood-Corpuscles. 



(1.) The colouring-matter or haemoglobin (Hb) (Hsemato-globulin, 

 Heemato-crystaUin) is the cause of the red colour of blood ; it also occurs 



