No. 467.] ZOOLOGICAL MATERIAL. 785 
II. Planarians are found on the under side of stones in run- 
ning water. They are usually abundant in a locality if found 
there at all. They may be removed from the stones by means 
of a thin wooden toothpick, and placed in a bottle of water for 
transportation. 
12. Earthworms. — The collection of earthworms should be 
attended to as early in the fall as possible, as dry or cold weather 
may make it impossible to get them later. It is well to lay in 
a supply of preserved worms during the spring or summer. 
Specimens to be kept alive should perhaps not be collected 
until after the first of October, but it will be unsafe to wait 
much longer. Each student will need two or three preserved, 
and one or two living specimens. 
The form used in the Zoólogical Laboratory of the University 
of Michigan is Lumbricus herculeus Savigny. The specimens 
range in length from about 6 to 11 inches, with an average of 
about 8 inches. They come out of their burrows on warm, rainy 
nights, usually lying extended with the posterior end of the body 
still in the entrance of the burrow. They are most abundant in 
old, rich gardens and lawns. Go out with a lantern and a pail 
after it has become quite dark; the harder it rains the better. 
By stepping lightly and not allowing the light to shine upon 
them too long, one may seize the worms with the hand. To 
catch them requires quickness and dexterity ; but they must be 
pulled gently from the burrow. 
When brought into the laboratory the worms that are to be 
preserved for dissection should be placed immediately in covered 
bacteria dishes (9 inches in diameter by 3 inches deep) between 
sheets of moist filter paper; the covers should be adjusted so 
as to admit a littleair. Not more than twelve specimens should 
be placed in a dish, as they will soon die if large numbers of 
them are left together. The dishes should be kept in a cool 
place, avoiding direct sunlight. In the morning the paper 
should be changed, and injured or dead specimens removed; 
the operation should be repeated as often as is necessary. After 
a day or two the worms will have eaten enough moist filter 
paper to clean the alimentary canal of earth, and are ready for 
preservation. 
