62 INVERTEBRATE ZOOLOGY. 



III. FORAMINIFERA 



These are marine and cover with their shells the bottom of the ocean over 

 vast areas, and often at great depths. In snch places the "ooze" dredged 

 from the bottom is mainly composed of Foraminifera shells. 



5, Ponr out a little of the dry ooze into a watch crystal and examine 

 with dissecting microscope. Find as many different shapes as possible. A 

 common form is the Globigerina form (several genera) a series of spheres of 

 different sizes, irregularly heaped together. Another common shape is Rota- 

 lia, and allied forms ;'fiat and consisting of several chambers arranged in a 

 spiral. 



6, Place a few shells on a slide under a dissecting microscope and add a 

 drop of HCl. What happens V Of what material do the shells consist ? 



7, [The experimental part of this will furnish material for the entire 

 class, and need not be performed by the student.] Boil gently a quantity of 

 ooze in a test-tiTbe of lO'j''-. This is to expel air from the separate chambers. 

 Allow it to settle and then decant off the 70 % and replace with 95 %. In the 

 same way add 100^ and turpentine, after which the preparation is brought 

 into a shallow dish. A stay of several hours in each liquid is advisable. To 

 prepare a permanent mount from this, pipette a drop upon a clean slide, drain 

 off the excess of turpentine and mount in Balsam. In this preparation ob- 

 serve the numerous pores, or foramina, through which in life the very numer- 

 ous filamentous pseudopodia are projected. 



IV. Infusoria. 



8, Place a handful of leaves, flower-stems, etc., with a pinch of sugar 

 in a beaker of water and allow it to stand a week or two, until the water is of 

 a greenish yellow color. Such water forms an " infusion." and will be found 

 filled with Infusoria. 



[In this as well as in subsec^uent experiments requiring time, make them as 

 stated, and pass on to the next, returning to these at the proper time.] The 

 Infusoria obtained by this experiment are mostly oval flattened forms, the 

 type being called Parmnoecium. 



8, cr- Bring a drop ui)on a slide, cover and examine. Study them in full 

 motion as well as you can. By a little skill you can keep a moving form iin- 

 der continual observation, keeping the left hand on the slide, the right one on 

 the focal screw and the eye at the microscope. The left hand follows the 



