VASCULAR SYSTEM OF PHERETIMA 359 
It seems reasonable to suppose that by the time the earth 
reaches the last rectal portion of the gut there is hardly any 
nutriment left in it for absorption, and hence we have the 
absence of the typhlosole as well as of internal blood-plexus 
in this region, both of these structures being the likely media 
for absorption of nutriment from the earth. A well-developed 
external network of capillaries is, however, present in the 
TEXT-FIG. 3. 
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WMH INI 
ty i} 
‘yy J 
Ist region 2nd region x dv. 3rd region 
Semi-diagrammatic representation of the intestinal blood-plexus 
in the three regions of the intestine. The Is/ region extends from 
the fourteenth to the twenty-sixth segment; the 2nd region 
from the twenty-sixth to twenty-three to twenty-six segments in 
front of the anus and the region includes the last twenty-three 
to twenty-six segments (rectal region). d.v.=dorsal vessel ; 
x=the place where there is a change from the regular geometrical 
plexus to the branching tree-like plexus of the rectum. 
rectal region and serves to supply blood to the wall of the gut, 
and also, being distributed amongst the chloragogen cells, 
allows the latter to take up the excretory products from the 
blood capillaries. 
In the second region, which is the most extensive (twenty- 
sixth segment to twenty-three to twenty-eight segments in 
front of the anus) of the three regions, we have a typhlosole 
as well as both the internal and the external plexus equally 
