CY STOP US CANDID US. 47 



Dust some conidia from a fresh growing plant 8 upon a 

 slide and mount with water ; 7 in about an hour, notice 



11. The small protuberance formed on one side of some of 

 the conidia, which opens and permits the escape of 

 the protoplasm in the form of several motile bodies, 

 zoospores, 



a. The shape of the zoospores, and the pair of 

 bright spots in each. 



b. Study the increment. 



c. Notice the pair of delicate vibratile cilia, by 

 means of which the movements are effected. Stain 

 with iodine, and the cilia can be seen more easily. 

 Note their length. 



d. The color imparted to the zoospore and its cilia by 

 the iodine. 



<?. Draw some zoospores, and also one or two conidia 

 which have not discharged zoospores, and one or 

 two empty ones. 



12. The sexual reproduction. Stain a section of an alco- 

 holic specimen of radish flower containing oospores 

 with chlor-iodide of zinc, and notice 



a. The numerous globular bodies, stained wine-red, 

 lying in the tissues of the radish, oogonia. 



b. Accompanying them, and stained the same, smaller 

 rounded bodies, antheridia. 



c. In some of the oogonia, a globular mass of 

 granular protoplasm, not completely filling the 

 oogonium, the oosphere. 



d. A slender tube passing from the antheridium to 



6 The conidia will germinate if sown at any time of day, provided the 

 specimens are fresh, but will do so more readily when sown in the morn- 

 ing from plants which have remained over night under a moist bell jar. 



7 Care must be taken that the water does not evaporate, and to guard 

 against this it is best to use a slide having a shallow cell. 



