ARTIFICIAL PRODUCTION' OF TUBERCLE. 13 



vidual granulations, or tliey may extend through considerahle spaces. They 

 generally, however, remain firm and hard. In some cases — though the 

 appearance is rare — they may form masses of the size of a hazel-nut, with a 

 diffluent creamy centre. 



When sections of the liver are examined with the microscope (Plate III. 

 figs. 4, 5), the semi-transparent portions, whether in granules or in confluent 

 masses, are found to consist of a new growth situated in the interlobular 

 tissue, or in what is called the capsule of Glisson, between the acini. The 

 tissue thus produced consists of cells uniformly imbedded in a delicate fibrous 

 network, in the meshes of which they lie. In size, the cells correspond to 

 those found in the new growths in other situations ; the ordinary size being 

 from l-3000th to 1,3500th of an inch in diameter. Some may reach the size of 

 the l-2000th to l-2500th of an inch. The nuclei average about the l-3600th of 

 an inch. These are strongly refracting, and have a distinct margin. The 

 contents of the cells are nebulous, and their outline is less distinct than that 

 of the nuclei. In some of the larger cells, double nuclei may occasionally be 

 seen. In some places, the cells are agglomerated into strings or rows, forming 

 elongated masses resembling those described as seen in the granulations 

 occurring under the skin, and to which the same interpretation is probably 

 applicable. 



The amount of this tissue between the acini varies. Sometimes these are 

 occluded over large spaces, or outlines only of the acini pressed aside may 

 remain mapping out the masses of new formation. The sections under the 

 microscope show that these latter always tend to assume a globular form, and 

 that at their margins the cells of new growth, which are strikingly different 

 from the liver-cells, pass up in lines between the network of cells of which 

 the acini of the liver are composed {d d d, fig. 4). The liver-cells appear to 

 atrophy in consequence of the progress of this growth, but they undergo no 

 further changes. There is no multiplication of their nuclei, as if they partici- 

 pated in the growth, and they undergo no special granular change. They 

 become pale and nebulous, with a fine molecular appearance ; and here and 

 there some fatty change when they are pressed upon by the growth. Both the 

 bile-ducts and the proper gland-tissue appear to be otherwise unaffected and 

 healthy. Little specks of fine granular degeneration may be seen scattered 

 through the masses of new growth, which in some spots pass into a more 

 complete molecular debris. 



The spleen (Plate I. figs. 2, 3) also enlarges very much ; sometimes to 

 two, three, or four times its natural size. I have measured it two inches and a 

 quarter long, one and a quarter broad, and half an inch thick. It also is 



