REPOBT OF THE SOCIETY 85 



No. D appears to be the same organism. It was isolated from the roots 

 of wilted sweet peas, and, all the writer was unable to secure infection with 

 it, it agrees very closely with the description given by Taubenhaus for F. lathyri. 

 The macroconidia are typical in shape, from 2- to 5-septate, mostly 3-septate, 

 which measure 17.5 — 35.0 x 2.6 — 6.1 u (29.5 — 4.2 u) The chlamydospores 



are comparatively small, round, and occur singly, in short chains, and in small 

 clumps. 



Growth on various media. 



In the limited time available it will be impossible to give the detailed 

 results of the various experiments cariied out under this hand. A brief discus- 

 sion of these results will be all that is possible. 



a. Effect of the medium on growth character s. 



There is a wide variation in the type of growth from an entire lack of aerial 

 mycelium with a tough leathery surface layer, as F. Orthoceras on iris leaf juice 

 agar, to dense aerial growth, as F. solani on Richard's solution. All gradations 

 between these extremes may be found and the different organism have various 

 abilities in this regard. The vigour of the organism is possibly involved, a vi- 

 gourous one producing aerial growth on more media. 



Colour varies widely within each species. It may be piesent on one medium 

 and absent on another. The intensity also -varies. However, there seems to be 

 a typical fundamental colour for each organism which will be produced to some 

 degree when any colour is present. The vinaceous colour of F. orthoceras is an 

 example of this. Harshbergex's nutiient solution agar with 2% dextrose is the 

 best medium for colour production. 



The character of the mycelium varies greatly but not constantly, and con- 

 sequently this charactere is suseless from the taxonomix standpoint. There 

 are variations in the width of the hyphea, cell length, and protoplasmic content. 



The production of chlamydospores is usual on certain types of media and 

 seems to be associated with a lack of proper nutrition. The sugar agars and 

 Harshberger's solution agar are examples of this type of medium. There is a 

 variation in the size, number and contents of these structures. 



The conidia from one of the most variable characters. Microconidia and 

 macroconidia appear on the different media in varying proportions. An abun 

 dance of conidia is seldom found when large numbers of chlamydospores are 

 present. The size of the macroconidia and their septation appear to vaiy about 

 a more or less constant, mean, and consequently the more measurements that 

 are taken the more nearly will this mean be approached . The great variation 

 in the percentages of the different types of septation also makes the observation 



