386 



THE NON- VASCULAR PLANTS 



(See Figure i8j.) These haustoria penetrate the epider- 

 mal cells of the lilac, and from them absorb food. Since 



the cells of the mesophyll 

 are not injured by it, 

 however, lilac leaves ap- 

 pear to get along pretty 

 well in spite of the mil- 

 dew. Numerous little 

 sporophores arise from 

 the mycehum, and it is 

 the abundance of spores 

 which makes the myce- 

 hum look like dust. 



This fungus, Kke bread 

 mold, also has a sex 

 method of reproduction. 

 The sex organs are very 

 small, but the structures 

 which result from the sex 

 process are not small. 

 They are big enough to 

 be seen with the naked 

 eye. They looklike 

 „ o ,,u J- J A,- , r dark-brown dots. They 



Fig. 183. — Albugo Candida. A kind of para- -' 



site (white rust) which attacks members of are Called asCOCarpS. 



the mustard family. The figure shows the The OUtsidc of them is a 

 appearance of a section of a mustard leaf 1 ■ , 



cut through one of the parts attacked. Note thlck-Walled CaSC, and the 



the way in which spores are produced. The inside of them is what 



top row of cells is the epidermis of the host. ■■ it j r u 



It is finally ruptured and the spores escape. '^^^ resulted trom the 



Note the way in which the hypha; (shaded) grOWth of the OOSpore. 



burrow between the cells of the mesoohyll ■r'^„ tin' " 1, 



and send little suckers (Aa««ma) into the -t^Or tniS OOSpOre iias a 



protoplasts. habit we have already 



