Preston Kyes 



41 



and with the sheaths of the- blood-vessels within the lobule. The 

 network is devoid of nuclei and the picture is that of a continuous 

 system of branching and anastomosing threads of fairly uniform caliber. 

 The extent of an individual fibril canuc^t be determined. 



Fig. 1.— Congested human spleen ; digested with pancreatin ; stained with 

 iron h?ematoxylin ; Zeiss, Obj. AA, Oc. 2. 



A. Capsule. 



B. Trabeculae of coarser framework. 



C. Intralobular framework. 



D. Intralobular capillary veins [Billroth]. 



E. Malpighian follicle with afferent artery. 



The network extends throughout the entire lobule between the 

 capillary veins and in a modified form within the Malpighian follicles. 

 Thus the arrangement is such as to outline in the digested specimens 

 all the structures appreciable in the undigested specimens. The gen- 

 eral distribution of the network throughout the lobule is interrupted 

 by irregularly, circular channels averaging 0.18 mm. in diameter. These 

 channels freely communicate with one another, and in thin specimens 

 appear as circular and oval lacunae surrounded by the framework of 

 the pulp cords. They represent the lumina of the intralobular capillary 

 veins first described by Billroth. (Fig. 1, D.) 



The arrangement of the fibrils immediately surrounding the capil- 

 lary veins is so modified as to form a definite framework limiting the 

 venous spaces. Continuing from the general network of the pulp cords 



