ALBUGO CANDIDA 123 



showing the attached chains of conidia and the mode 

 of formation of the latter. In this drawing make 

 the conidia at least 5 mm. in diameter. 

 6. Include in your notes at this point a brief descrip- 

 tion of the germination of the conidia. (The infor- 

 mation should, if possible, be obtained from 

 material supplied by the instructor, otherwise from 

 lecture or reading.) 

 G. Sexual Reproduction: 



1. The sexual reproduction of Albugo generally occurs 

 in other parts of the host-plant, and later in the 

 season than the asexual reproduction. The tissues 

 of the host-plant containing the sexual organs of the 

 parasite are generally enlarged (hypertrophied) and 

 distorted. 



2. In the material given you observe the large spherical 

 oogonium, containing a single oosphere or egg 

 surrounded by the so-called periplasm or epiplasm. 

 Is the oogonium sessile or stalked? 



Closely appressed to the oogonium at some point 

 find the smaller antheridium. Describe its shape, 

 and general appearance. Are its contents separated 

 from those of the hypha by a cross- wall? 



4. How does the male gamete (sperm) pass through 

 the oogonium- wall and periplasm to the egg? 



5. If your material is suitable, observe and describe 

 the mature fertilized egg (ob'sperm). After fertili- 

 zation the periplasm becomes transformed into the 

 wall of the oosperm. Note the exospore (of one 

 layer) and the endospore of three layers. 



6. Make drawings showing all features observed un- 

 der G. 



H. General Questions: 



i. Explain how Albugo is disseminated. 



