DEVELOPMENT OF LOBULE OF PIG’S LIVER 307 
old. He does not state, however, whether or not this con- 
nective tissue contains true collagen fibrils. 
Fig. 6 Interlobular septa of liver of a pig three weeks old. Mallory’s triple 
connective-tissue stain. 250. 
Fig. 7 Same, two months old pig. 
The exact manner in which the connective tissue of the septa 
is laid down, that is, whether the collagen fibrils have their 
origin from fibroblasts situated in the portal canals and push 
their way out into the interlobular reticulum or whether the 
fibroblasts first migrate and give rise to the collagen fibrils 
