874 Leukemia of Mammals. 



dullness over the liver increases backwards and downwards 

 to a level with, the point of the shoulder ; in case of very great 

 enlargement, the posterior upper border of the liver may be 

 felt in the anterior angle of the right flank. In horses the 

 dullness over the liver appears first in the region of the last 

 intercostal space on the right side. The recognition of a possi- 

 ble enlargement of the mammary or salivary glands causes no 

 difficulty. 



The blood appears pale red, sometimes chocolate brown, 

 stains less intensively, coagulates slowly, causing on the upper 

 surface of the coagulum a grayish-white layer or an adhering 

 grayish-white deposit consisting of white blood corpuscles. 

 The blood of leukemic horses separates on standing into three 

 layers, a lower violet-colored consisting of red blood cells, an 

 upper formed by somewhat transparent yellowish fibrine, and 

 a middle grayish-white consisting of white blood corpuscles, 

 the layers may appear of different heights in proportion to 

 the number of white blood corpuscles. The blood of other 

 leukemic animals separates on coagulating into two layers, of 

 which the lower, violet-colored, is formed by red blood cor- 

 puscles, the upper grayish-white, milk-like being formed by 

 fibrin and white blood corpuscles. 



An increase of white blood corpuscles may always be shown. 

 While normal blood contains at most 4 to 6 white blood cor- 

 puscles in a field, they are seen in leukemic blood in much 

 greater numbers, sometimes nearly as many or even as many 

 as the number of red blood corpuscles. On counting, the 

 number of white blood corpuscles is found considerably in- 

 creased, as compared with the normal (8,000-12,000) and the 

 numerical relation between the white and red blood corpuscles 

 (in normal conditions 1 :400-800) becomes much less, as low as 

 1:5 (Berndt) and may be even less (in man the relation of 

 2:1 has even been observed [Sticker])? A diminution of red 

 blood corpuscles may also always be demonstrated, and their 

 number per cubic millimeter of blood may diminish from 7.5 

 millions to two millions (Nocard). 



The establishment of the morphological condition of the 

 white blood corpuscles in stained preparations is of especial 

 value (see p. 865). In lymphatic leukemia lymphocytes are 

 found to be increased (Wolff, de Jong, Marek), while the 

 number of true leucocytes remains normal or comparatively so. 



The lymphocytes appear uniform in size or slightly and sometimes even 

 considerably . larger than the red blood corpuscles ; their large roundish nucleus 

 is stained less with basic dyes (methylene blue, methyl green) than the proto- 

 plasm surrounding the nucleus in the shape of a ring; in some large examples, 

 however, both are sometimes stained uniformly pale (Plate X, Fig. 1-a, b). 



In the myelogenic (myeloid) leukemia, on the other hand, 

 the number of lymphocytes remains unchanged, and the 

 leucocytes are considerably increased ; there also appear in the 

 blood unripe, mononuclear forms, which possess granulated 



