Apr. 30,1917 
Morphology of Normal Pigs' Blood 
137 
times as wide as an average red corpuscle. In recognizing these cells two 
things are important: First, the great size of some of the cells, and second, 
the lighter stained nucleus than the lymphocytes and the larger amount 
of visible cytoplasm. This cytoplasm in a well-stained spread is light 
bluish green in color, with a few fine darker granules throughout. 
We have found that it is sometimes difficult to determine whether to 
place some of these mononuclear cells into the class of lymphocytes or 
large mononuclears, as there are quite a number of border-line cells. 
PolymorphonuclEars. —The nucleus in this variety is several-lobed; 
the lobes are nearly always connected, sometimes with threadlike con¬ 
nections, but more often the connecting portions are as wide as the lobes, 
so that the nucleus assumes the form of a deeply stained spiral coil. It 
may be roughly S-shaped or Z-shaped. In well-stained spreads the cell 
body contains many fine granules so small that they appear as brick-red 
points. The entire cell is about the size of the largest lymphocytes. 
Sometimes the lobes of the nucleus are not connected and stand out in 
such a way that they can. be easily counted, and average about six to 
seven in number. 
Eosinophiles. —Giltner states that the eosinophiles are comparable to 
the polymorphs in size, or are slightly larger, and have a bilobed nucleus, 
the two parts of which are connected by a thick band and take the basic 
stain. The cell body is granular, but the granules are not nearly so large 
and distinct as those found in the eosinophile of the horse, but are more 
numerous (estimated at 100, more or less) and have a strong affinity for 
the eosin stain. 
In our work we have found that the eosinophiles are usually slightly 
larger than the polymorphs. The nucleus is darkly stained, but is lighter 
than the nucleus of the polymorphs. The lobes are wide, and there may 
be one to four lobes in each nucleus. The lobes are usually connected 
by broad bands, but we sometimes find a nucleus containing two large 
lobes which are not connected. No attempt was made to count the 
number of granules. 
Mast cells. —Giltner 1 states the mast cells in the blood of the pig 
are about the same size as the eosinophiles and have a similar-shaped 
nucleus, but that the cell body possesses granules of a smaller size, more 
distinct in outline, and of a purple color. The granules lie both in the 
cytoplasm surrounding the nucleus and in a position superposed to the 
nucleus. 
In the blood of some pigs we have found mast cells about the size of 
eosinophiles, which closely resemble a large lymphocyte except that the 
space in the cell body not occupied by the nucleus is filled with dark- 
blue granules. Granules are also quite numerous over the nucleus in 
many of these cells, but the number of granules placed in this location 
Giltner, Ward. Op. dt. 
