JEHANGIR FARDUNJI DASTUR. 207 



begins to take place on the side or sides where the protoplasm 

 is present. If the protoplasm disappears from both the new cells 

 formed by the septum there is no thickening on it. This thickening 

 of the septum is found to be of pure cellulose. It is dissolved by 

 cupric ammonium hydrate and sulphuric acid, no way affected by 

 caustic potash, alkali carbonates and ammonia and stains blue or 

 violet with all the cellulose iodide reagents. This thickening on the 

 septum is found not only in the vegetative hyphpe but also on the 

 septum of the oogonial stalk within the antheridium and on the 

 antheridial septa as well. 



These cellulose plugs in hyphee, and cellulose deposits on their 

 walls and septa, have been observed by me in the hypha) of Pli. 

 Faberi also. 



The sporangia are composed of pure cellulose, except their papil- 

 la. As already stated they have on their walls irregular cellulose 

 thickenings. At the point of attachment to the sporangiophores 

 generally a thickening has been found, which is of pure cellulose 

 and not of callose as observed by Mangin 1 in the other 

 Pero nosporace gb. 



The " resting " conidia have been found to possess three walls ; 

 the outer, thin and hyaline, is closely applied to the central thick 

 and yellowish wall and escapes observation unless it is stained ; the 

 innermost wall is thicker than the outer but thinner than the 

 central wall, its colour is masked by the yellow of the latter, to 

 which it is not closely attached. Very young " resting " conidia 

 apparently stain yellow with the iodide reagents for cellulose, but 

 if they be closely examined a faint coat can be detected around them. 

 In very young intercalar " resting " conidia, which have not become 

 spherical but are ellipsoidal, a quantity of cellulose is collected at the 

 ends. When mature the " resting " conidia colour blue or violet 

 with iodine and phosphoric acid or with any other iodine cellulose 

 reagent, as the outer wall has become thicker. If they be first treated 

 with hydrochloric acid for a couple of hours and then for a short 



1 Mangin, L. Sur la disarticulation des conidies chez lea Pfronosporks. Bull. Soo. Bo . 

 Fr., XXXVIII, 1891, p. 234. 



