THE EARTHWORM AND HIS WORK. 151 
Next it goes on to the gizzard, which is filled with little 
stones to make a mill for grinding the food. After 
being ground, the food passes into the intestine, where 
the nutritious matters are taken into the blood and 
carried to the tissues of the body, while the part which 
cannot be digested is cast out at the end of the body, 
usually near the opening of the worm’s burrow. The 
blood which carries the nutritious matter to the parts 
where it is needed is of a reddish color, but the color 
is in the liquid part of the blood and not in the corpus¬ 
cles, as is the case in our own bodies. 
Respiration. An examination of the earthworm’s 
body reveals neither spiracles nor gills. In fact it has 
no breathing organ, but takes oxygen from the air at 
all parts of its skin and sends out or excretes carbon 
dioxide and other impurities at the same time. The 
blood-vessels are so near the surface that the necessary 
interchange of gases can easily take place as long as 
the worm’s skin is moist. Worms cannot live long in 
the sunlight or in dry sand because they cannot breathe 
under such conditions. 
Reproduction. On the under side of the fourteenth 
and fifteenth segments in a common species are to be 
found some small openings which lead to the ovaries or 
egg-producing organs. Several segments in front of 
these, there are tiny holes in the grooves between the 
segments. These open into receptacles containing the 
male cells or sperms. 
When the time for depositing eggs arrives certain 
glands of the clitellum become very active and pour 
out on the surface of the body a fluid which hardens 
into a tough membrane, making a girdle around the 
body, the reproductive girdle. A jelly-like liquid 
remains between the girdle and the body while it is 
gradually pushed forward. When the girdle passes the 
openings to the ovaries the eggs are discharged into it, 
and when it passes the segments from nine to eleven 
the sperms pass into the fluid with the eggs. The 
