122 OROBANCHE AS A rARA«TTE TN BTHAR 



Seed 0. cermia brinjal was infected upon eight pots of tobacco, four of 

 which received 1 oz. each of sodium nitrate. In the first six weeks " tokra " 

 came up in all the non-nitrate pots and in two of the nitrate pots. In the 

 two remaining nitrate pots it did not appear until after the lapse of three 

 months. Seed 0. cernua (omato infected upon tobacco behaved in much the 

 same manner, hut in one pot, which had received sodium nitrate, " tokra " 

 did not appear. 



Seed 0. indica cabbage was infected upon four pots each of tobacco, 

 mustard, cabbage, and turnip ; half of the pots had received 1 oz. each of 

 sodium nitrate. No "tokra" at all appeared upon the tobacco; "tokra" 

 (0. indica) came up in all the pots of mustard and turnip and in two of 

 the pots of cabbage. It did not appear in the two cabbage pots which 

 had received nitrate, and in the mustard and turnip nitrate pots it was 

 distinctly later in appearing than hi the non-nitiate pots. Seed 0. indica 

 mustard behaved in exactly the same way as the seed 0. indica cabbage when 

 infected upon tobacco, mustard, cabbage, and turnip. Here, again, " tokra" 

 was much later in appearing in the nitrate pots and m one nitrate pot of 

 cabbage did not come up at all. Seed 0. indica turnvp gave the same 

 result, coming up on mustard, cabbage and turnip but not appearing in 

 the tohacco pots. "Tokra" was again late in the nitrate pots and did 

 not appear at all in the cabbage pots which had nitrate. 



It has been mentioned previously in this account that 0. indica is some- 

 times found parasitic upon tobacco. Seed of 0. indica from this source was 

 accordingly used to infect eight pots of mustard and four pots of tobacco. In 

 the eight pots of mustard "tokra " only appeared in two pots and in each 

 of these pots there was only one "tokra" and that a very small and weak 

 specimen of 0. indica. In all the tobacco pots "tokra" appeared very 

 abundantly ; it was appreciably later in those pots which had received nitrate 

 but still each of the four pots had about 50 " tokras." In every case this 

 "tokra" was 0. Mirfimandwas morphologically indistinguishable from the 

 " tokra " which had appeared in the mustard, cabbage, and turnip pots 

 when these were infected with seed of 0. indica from cabbage, mustard, and 

 turnip hosts. Yet these latter varieties of 0. indica seed failed to give 

 any "tokras" when infected upon tobacco. It appears therefore that 

 seed of 0. indica collected from mustard, cabbage, and turnip hosts will 

 infect these hosts and will not infect tobacco, while seed of 0. indica 

 collected from tobacco host will infect tobacco and will hardly infect 

 mustard at all. 



