40 CAUSE AND NATURE OF CROWN-GAEL 



it will be found to have changed color in places, the contents 

 of certain cells varying from dark brown to deep orange or red. 

 If sections be made of this tissue and examined in water, these 

 cells will be found to be completely filled with dense protoplas- 

 mic bodies. As the tissue becomes older these bodies deepen 

 to dark orange and finally become reddish brown or almost black. 

 If the gall be allowed to decay, they appear as dark oval bodies 

 in the decayed tissue. These, possibly, are sclerotia or resting 

 stages of the Plasmodium. November 12, 1899, a large number 

 of these bodies, which vary from 15 to 40 ," in diameter, were 

 carefully selected from the decayed tissue of an old gall and placed 

 in distilled water. They were washed through several changes 

 of water and used in inoculating eight almond seedlings. On 

 January 4, when first examined, three of the inoculated plants 

 were diseased. At the time that this examination was made 

 six small almond seedlings were pruned back to small cut- 

 tings about four inches long, consisting of two inches of the 

 root and two inches of the stem. The root end of three of these 

 cuttings was split open and a quantity of the washed sclerotia 

 inserted. The shoot end of the other three was treated in a 

 similar manner. The cuttings were kept in a moist chamber 

 for one month and examined from time to time. At the end of 

 the experiment one of the cuttings split in the stem had two 

 galls, a millimeter or more in diameter, developing on the split 

 surface near the pith. In both instances they were beneath 

 buds on the stem. 



THE EFFECT OF THE PLASMODIUM UPON THE CYTOPLASM OF 

 THE HOST CELL. 



Before describing the fruiting phase of the organism I desire 

 to call attention to the effect of the plasmodium upon the host 

 cell. This part of the investigation was worked out from the 

 study of serial sections, fixed in Flemmiug and stained 011 the 

 slide. The work was verified, so far as possible, from a study 

 of fresh material. Flemming rapidly darkens the hypertro- 

 phied tissue in the process of fixing, particularly that portion 

 infested by plasmodia. 



