154 



PRACTICAL BOTANY. 



3. Mount some of the filaments taken from the blue 

 ring in 30 per cent alcohol. Compare the distal ends of 

 these with those from the white ring. Do these bear 

 gonidia? Make another mount from the central green 

 portion. State how the distal ends of these compare with 

 the distal ends of filaments from the blue and white rings. 

 Compare the septa in the three mounts. Is Penicillium a 

 unicellular or multicellular plant? 



4. Examine the gonidia. Show by a drawing the ar- 

 rangement of the spores. To the naked eye the spores in 



mass appear blue or green. Can 

 you distinguish either of these 

 colors under the microscope? 

 The color is not due to chloro- 

 phyl. No chrornatophores can 

 be distinguished. Mount some 

 spores in alcohol, stain with 

 hyematoxylm, and try to make 

 out a nucleus. Treat another 

 mount of the spores with 

 Schultze's solution, and describe 

 the effects on the cell wall, nu- 



' 



cleus, and cell contents. Treat 

 Bother mount with caustic pot- 

 ash and describe the effects. 



5. Make hanging drop cultures of the spores. Set 

 aside in warm places and examine from day to day to 

 watch the development of the spores. Make drawings, 

 showing the development of successive stages. 



6. Mount a little of the mycelium in 30 per cent alco- 

 hol, tearing it apart with needles. Notice the granu- 

 lar protoplasm. Do you find vacuoles ? Treat with 

 Schultze's solution. Of what kind of cellulose is the cell 

 wall composed? Mount some more of the mycelium in 

 alcohol, stain with haematoxylin, and make out the nuclei.. 



FIG. 87. Pemcillium (jlaucum. 



m, a portion of the mycelium ; 



