374 R - w - GLASER AND J. W. CHAPMAN. 



indication of a diseased nucleus seems to consist in the flowing 

 together of the chromatin into a lump in the middle. Then out 

 of the achromatic substance the polyhedra arise as very minute 

 individuals. (Fig. 2, Plate I.) They gradually increase in size 

 and probably most of the chromatin is also used up during the 

 synthetic process. As the polyhedra grow, they become more 

 and more refractive, stain with difficulty, and the nucleus be- 

 comes hypertrophied. The late stages of these hypertrophied 

 nuclei are more than twice as large as the largest normal nucleus. 

 (Fig. 2, Plate I, and 3, 4 and 5, Plate II.) This swelling of the 

 nucleus is due to the increase in size of the polyhedral bodies which 

 stretch the nuclear membrane. During the earlier stages of the 

 disease the polyhedra are somewhat rounder than the larger ones 

 found later on prior to death. This can be accounted for by the 

 fact that, as the polyhedra grow, they become so closely packed 

 within a nucleus that they press upon one another and thus the 

 more or less polygonal shape is produced. As the polyhedra 

 grow and become more refractive the remains of the chromatin 

 lump disappears and there remains simply the nuclear membrane 

 enclosing the polyhedra. (Fig. 2, Plate I, and 3, Plate II.) 

 Finally the nucleus disintegrates, and the polyhedra are found 

 free in great numbers in smears of dead caterpillars. (Fig. 6, 

 Plate II.) We believe (and this belief is based on morphological, 

 chemical and experimental evidence) that the polyhedral bodies 

 are degeneration-products of the disease products of nuclear 

 disintegration. This view may not seem so improbable if one 

 reviews some of the literature dealing with a few of the diseases 

 in higher animals. 



HYDROPHOBIA (RABIES). 



In 1903, Negri described certain bodies occurring in the nervous 

 system of animals dying of rabies. The bodies seem to be specific 

 to the disease, and are of great assistance for diagnostic purposes. 

 The Negri bodies vary in size, measuring from .5 to 25 n- They 

 are round, oval or angular in outline and are found in the proto- 

 plasm of the nerve cells and their processes. The bodies occur 

 in all parts of the nervous system, but are most common in the 

 Purkinje cells of the cerebellum and especially in the cells of 

 the cornu Ammonis. The virus of hydrophobia passes through 



