80 LABORATORY AND FIELD EXERCISES 



2. Sexual reproduction. Mount fruiting plants of Vauelieria 



after teasing them apart with dissecting needles in a 

 drop of water. Search for reproductive branches with 

 a low power. 



a. Female gameiangia and gametes. Search for greatly 



swollen and shortened lateral branches representing 

 the female gametangia. 



(1) Do these reproductive branches differ from the ordi- 



nary branches of the plant body except in size ? 

 What is the nature of the protoplast and of 

 the embedded chloroplasts in these reproductive 

 branches ? Do you find a projecting beak, or ros- 

 trum, at one side of the reproductive branch ? It 

 is at this point that the cell wall of the game- 

 tangium breaks down and allows the male gamete 

 to enter the egg. 



(2) In properly prepared material the nature of the 



protoplast and the location of the chloroplast and 

 nucleus may be seen. Observe carefully with the 

 high power. 



b. Male gametangium. The male gametangium is usually 



represented by a curved branch near the female 

 gametangium. 



(1) Note the nature of the protoplast of the male 



gametangium. Contrast it with that of the 

 female. Male gametes cannot usually be found 

 in VaucJieria. If they have been expelled, the 

 gametangium looks light-colored and empty. 



(2) Draw a portion of a plant bearing male and female 



gametangia. Detail the female gametes. 



3. Vegetative and asexual reproduction. Vegetative reproduc- 



tion occurs in Vauclieria by means of nonmotile repro- 

 ductive branches which are merely swollen, club-shaped 



