THE EARTH-WORM. 47 
muscular ring called the gizzard. From this pro- 
ceeds the broad intestine, which is constricted at each 
septum Examine different portions with the mi- 
croscope. 
11. Reproductive system.—Pour off the water from the 
saucer, and put in clean. Observe the large white 
bladder-like testes, two on each side, the anterior 
pair bilobed. The testes of each side are united by 
a median reservoir, upon which lies the large fim- 
briated openings of the vasa deferentia, two on each 
side. These unite into a single duct on each side, 
which open on the fifteenth segment. Examine a 
portion of one of the testes with your highest power. 
Numerous bundles of spermatozoa will be seen not 
quite mature, and having no movements. With a 
curved needle turn back the testes on one side, and 
observe, in front of and between them, the four dead 
white globular spermathece, or receptacula seminis, 
two on each side. Examine one with the microscope, 
and notice that the spermatozoa are not in bundles, 
but free. If the animal has not been dead too long, 
they will be seen in active movement. These are 
the spermatozoa of another individual. 
12, Search carefully for the ovaries. They are small pear- 
shaped bodies attached to the posterior surface of 
the septum between the twelfth and thirteenth seg- 
ments. They are very difficult to see, except when 
distended with ova. The oviducts are not attached 
to the ovaries, but commence with wide open mouths 
in the thirteenth segment, and pass into the four- 
teenth segment, where they open to the exterior in 
front of the vasa deferentia. Examine the ovaries 
with the microscope to see if they contain any ova. 
