AMOEBA 37 



croscope look through it toward the light and adjust the draw- 

 tube until the lines and figures in the field of the ocular become 

 most distinctly observable. 



These lines are always the same distance apart regardless of 

 the power of the objective used but since the size of the object to 

 be measured varies with the objective used it become necessary 

 to find the value of the ocular divisions for the different object- 

 ives. When used with a low power (Spencer Lens Co. 16 mm.) 

 objective a single one of the smallest divisions of the ocular scale 

 has the value of 0.0078 mm. With the high power (Spencer 

 Lens Co. 4 mm.) objective each of the smallest ocular divisions 

 has the value of 0.0017 mm. 



To measure an object under the microscope find the number 

 of smallest micrometer units in its length (or other dimension) 

 and multiply that number by the value, as given. above, of a single 

 ocular unit for the objective you are using. 



REFERENCE 



Gage, Simon Henry. 1917. The Microscope, An Introduction 

 to Microscopic Methods and to Histology. Comstock 

 Publ. Co. 



AMOEBA 



Classification : Phylum Protozoa, Class Rhizopoda, Order 

 Lobosa. 



1. METHOD OF EXAMINATION. Upon a clean glass slide 

 mount a small piece of the ooze containing Amoeba. Cover with 

 cover glass. Note appearance under low power. From .time 

 to time add a drop of water on the slide at the margin of the 

 cover glass to replace loss by evaporation. If a full answer can 

 not be given at once make temporary notes, reserving the final 

 answer until all the observations are completed. 



2. GENERAL FORM. Is the form constant? Is there any 

 plane of symmetry? Anterior or posterior end? Is there a char- 

 acteristic form or shape? Notes required. 



