The relatively high percentage of luemoglobin depends upon increased aver age size of the corpuscles and in sonic cases on the presence of an unusual number of colored and minute mierocytes. It also depends. in a meas ure, upon the time at which the exami nation is made. The icteric color of the skin and the dark mine are caused by Pathology.—The two prevailing the ories as to the pathogenesis of pernicious are the following: 1. That the disease is due to breaking up of the blood-corpuscles (htemolysis). 2. That, owing to some defect in the blood-mak ing (112ernogenesis), the blood becomes vulnerable to the destructive influence of micro-organisms.
dissolution of the red blood-corpuscles, and the hremeglobin estimated at one of these periods will thus be higher, owing to the more highly colored plasma. The red blood-corpuscles show marked signs of reversion to the type' of blood which is normal in the cold-blooded animals. F. 1'. Henry (Amer. jour. of Med. Sciences, Aug., 1900).
Besides the above, there is a species of degeneration closely resembling co agulation-necrosis, and an alteration of the corpuscles, characterized by the ap pearance in their interior of one or two corpuscles composed of modified hwmo globin,—digeneration hemoglobinemique. The process of regeneration is mani fested by the presence of nucleated red corpuscles, which are divided by Ehrlich into two varieties: the normoblasts and the megaloblasts, the former correspond ing to the hmmatinie evolution of adults, the latter to that of the embryo. The nucleus of the normoblast is extruded to form a new red corpuscle, while the nucleus of the meg,aloblast is absorbed.
Fresh blood shows nucleated red cor puscles of large size, divided by Ehrlich into megalocytes and gigantocytes. Others are termed macrocytes.
Furbringer has shown that a case is to be considered as one of true perni cious anemia only when one-fourth of the red corpuscles are macrocytes.
The presence of megaloblasts is a sign that certain pathological changes are taking place in the red marrow rather than a distinctive feature of pernicious anemia. The macrocytes and metrocytes are more characteristic of pernicious anmmia. because they are the direct pre cursors of the large red marrow-cells. Engel (Wiener med. Woch.. No. 20, '98).
By the subcutaneous injection of the muriate of phenylhydrazin into animals a condition of the blood similar to that in pernicious anemia is obtained. The view that pernicious anemia is a true ha-moglobinremia questioned. S. Kami
ner and R. Rohnstein (Berliner 'din. Woch., July 30, 1900).
Misshapen corpuscles (poikilocytes) are very frequently observed, oftener, indeed, than in any other affection.
Many small, imperfectly developed cor puscles (microcytes) are generally found.
In marked cases corpuscles endowed with motion are occasionally observed.
Bed blood-corpuscles of normal blood are motionless. The elements observed in eases of high degree of anmmia are endowed with four kinds of motion: 1. A movement of the entire mass of the corpuscle. 2. The projection of mobile prolongations. 3. A movement of oscil lation, manifested slowly by minute cor puscles. 4. A movement which results in changing the position of the cor puscles. These movable corpuscles are bodies arrested in their evolution and still retaining the contractile properties of the hrematoblasts from which the red corpuscles originate. On superficial ex amination they might readily be mis taken for parasites. Hayem (La Mede eine Moderne, Feb. 20, '90).
[Several years ago I observed distinct movements in the red corpuscles in a case of pernicious anaemia, but made no public mention of the interesting fact. F. P. HENRY, Assoc. Ed., Annual, '91.] Large number of amceboid corpuscles found in fresh-blood preparations, larger than red corpuscles, and possessed of very active movements. Perlcs (Medical Press, June, '93).
[In view of the fact that the red blood corpuscles of pernicious anmmia have been observed by Hayem and others to be possessed of amceboid movements, I would hesitate, in the absence of further proof, to regard the bodies described by Perks as other than degenerated blood constituents. F. P. HENRY, Assoc. Ed., Annual, '94.] Small, mobile bodies observed, staining the same as red corpuscles and resem bling fragments of hmmatins, thought to possess pathognomonic value. Senator (Le Bulletin Mkheal, May 26, '95).
Study of fifty cases. Most typical points in the blood: 1. A reduction of the number of red cells to about 1,000, 000. 2. The absence of leucocytosis. 3. Pos7.1bly a relatively high percentage of hemoglobin in some eases. 4. Increase in average diameter of the red cells. 5. The presence of large number of poly chromophilie red cells. 6. The presence of nucleated red cells, a minority being normoblasts. 7. The presence of mye locytes. 8. A relatively high percentage of small lymphocytes at the expense of the polymorphonuclear cells. Cabot (Boston Med. and Surg. Jour., Aug. 6, '90).