84 TYPE STUDIES 



2. The wall of the spore case. Has it a cellular structure ? 



3. The thread- or net-like structure, capillitium, -within the spore case 

 and the powdery spore mass. 



B. Under h.p. draw a portion of the capillitium, showing markings, and a 

 group of spores. 



69. The Plasmodium. This stage in the life history, when available, may 

 be made the subject of very interesting studies on the structure and behavior 

 of protoplasm. 



A. Mount a small portion and examine under low and high powers. Note 

 its consistence, structure, and contents. Describe and identify the food 

 contents as far as possible. Is starch present ? Are oils or fats pres- 

 ent ? Do you find any microscopic organisms which have been ingulfed 

 by the Plasmodium? 



B. Place the Plasmodium on moist blotting paper under a bell glass. 

 Devise experiments to determine its reaction : 



1. To bright illumination coming from one direction, with darkness 

 or faint illumination on the other side. 



2. To warmth on one side. 



3. To moisture on one side contrasted with dryness on the other. 



C. Should the Plasmodium begin to fructify, trace and describe the devel- 

 opment of the spore cases. 



70. The flagellate-like stage of a slime mold. Try to germinate fresh spores 

 in a hanging drop (Sec. 204) or a covered watch glass. Use water in which 

 decaying wood has been soaked. Study the structure and habits of the 

 motile protoplasts derived from the spores ; also the amoeboid condition, 

 myxamceboe, which follows, and trace if possible the union of the myxa- 

 moebsB to form a new Plasmodium. 



Eeference (to slime molds). Macbride, 38. 



THE BLUE-GEEEN ALG^, OR CYANOPHYCE^ 



71. Field work on the blue-green algae. Good displays of the blue-green 

 algBB may be found in open drains and stagnant pools which are somewhat 

 foul. Ditches and pools in salt marshes will furnish excellent material. 

 Slimy, dark, green growths on the surface of damp flowerpots, woodwork, 

 and earth are frequently composed of these growths. Water blooms are 

 generally made up of either blue-green algse or Eugl^a. 



Make collections in bottles, carefully noting the habitat, and bring to the 

 laboratory for study. 



72. Unicellular blue-green algse. Material of Glceocapsa or Chroococcus, 

 Glathrocystia or CodospJusrium is excellent. Study and draw : 



1. The form and arrangement of the cells and gell colODies, 



