152 



The apparent paucity of saltation in the strains other than H. No. 1 

 may be due in large part to the fact that these strains have been cultured 

 to much less extent, though there is also evidence that H. No. 1 really is 

 more actively saltating than are the other strains; indeed several strains, 

 as H. No 2 and H. No. 29, have given no evidence of sal tattoB-r- -Saltation 

 seemed to be as frequent in cultures derived from single conidia as from 

 other cultures. 



SALTATIONS OCCURRED ON VARIOUS MEDIA 



Saltation was not confined to corn-meal agar, but was seen to occur 

 also on green-wheat agar and on washed agar. The discrepancy in conidial 

 measurements on two shoots (one in plate e and one in e' , cited on p. 12i) 

 may have been due to saltation on the washed agar. H. No. 34 as well 

 as H. No. 1 showed saltation under standard conditions, that is, on washed 

 agar on which wheat shoots were laid. Several of the shoots bore only 

 sterile, white aerial mycelium, while the others were black owing to the 

 usual number of conidia. Repeated transfers demonstrated the perma- 

 nence of these characters. 



SALTATIONS AND MODIFICATIONS OCCURRING IN 

 TEST-TUBE CULTURES 



Certain cultures received from correspondents under the label Hel- 

 minthosporium remained largely or quite devoid of conidia. The fol- 

 lowing are brief descriptions of such Helminthosporiums. 



H. No. 11, of which graph of conidial length is given in Fig. S (cf. 

 with Graph 42, Fig. K) and conidial-breadth in Graph 101, Fig. V, dif- 

 fered in general colony-characters from H. Nos. 1, 3, etc., but most mark- 

 edly in that it remained for the most part without conidia. Conidial 

 septation is given in Fig. T, Graph 87. 



H. No. 12, which was received under the label "H. gramineum (?)" 

 evidently had sometime borne conidia, but transfers to many media under 

 many conditions gave me none in any case. 



H. No. 17, also labeled H. gramineum, under standard conditions 

 on wheat and corn usually produced mycelium with no conidia, though 

 in one case one wheat shoot gave conidia, while five others in the same 

 dish gave none. From this one shoot the conidial-length Graph 97 (Fig. 

 U) was made. 



It seems to me that the three cases just mentioned should be regarded 

 as those of saltants which have outstripped their originals in the test- 

 tube conditions, while the rare cases in which they do bear conidia, par- 



