176 



The asci arise between the epidermal cells and the true 

 cuticle and break through the cuticle toward maturity. 



Each ascus contains at maturity a large number of 

 small spores though it is probable that in younger stages 

 the typical condition is the 8-spored ascus. These original 

 8 spores however luultiply to a large extent within the as- 

 cus resulting in the much larger number that is to be 

 found in the mature asci. The asci in the material we 

 have examined are from 50 to 75 mu long and from 15 to 

 25 mu wide. The spo.res measured vary from 1.5 to 2.5 

 mu in diameter. 



As has been mentioned in the discussion of the syrapto- 

 moloy of the disease, the asci arise in small roundish 

 areas upon the surface of the leaf. In the original de- 

 scription of this fungus Desmazieires states that the 

 spots arise on the lower surface of the leaf but this is 

 certainv not uniformlv the case. We have no- 

 ticed that in Qucrcus vchitina, the black oak, the spots 

 are generally upon the lower surface only. The same fact 

 is recorded for this species by Robinson 1887. In Quer- 

 cus nigra, the water oak, and some other species the spots 

 occur on both the lower and upper surfaces of the leaves. 

 In all the species examined these spots are at first rather 

 definite but sooner or later several of the spots fuse to- 

 gether so that the spore bearing areas became very in- 

 definite and large. 



Like many of the fungi the species under consideration 

 has been referred to under a rather large number of 

 names in the past. Desmazieres in 1848 published the 

 new genus Ancomyces Mont. & Desm. to include the sin- 

 gle new species Ascomyces cocrulescens Mont. & Desm. 

 But the genus Tophria had been established by Fries in 

 1815 who assigned to it but one species, Taphria populina, 

 now known as Taphria aurea. Fries in 1825, 

 however, complicated matters by altering his first 



