130 Mortier F. Barrus 



The viability of the seed also is affected according as the mycelium 

 has or has not penetrated beyond the epidermis which protects the embryo. 

 ( iain (1898 and 1899) says that 10 per cent of the affected seed planted 

 did not germinate, 8 per cent germinated but did not grow, and 36 per 

 cent, although affected, were viable; while 46 per cent having only the 

 integument but not the cotyledon affected produced healthy plants, as 

 the fungus cannot produce fructifications unless it has penetrated into the 

 cotyledon. Seed affected to one-twentieth of their volume are not viable. 

 Gain says also that the disease can be quickly communicated from one 

 seed to another by contact, or by inoculation with spores. Halsted (1892) 

 states that only half of the diseased seed germinated, and those that did 

 germinate produced plants of a sickly nature. Observations made by 

 various other workers seem to prove that affected seed germinates poorly. 

 The experience of the writer indicates that the percentage of germination 

 of anthracnose-affected seeds is dependent mainly on the tissue affected 

 and the area of the lesion. If the embryo or the tissues near it are affected, 

 the seed usually will not germinate. When conditions are far from 

 optimum for germination of bean seed, affected seeds often do not 

 germinate, but neither will healthy seed germinate well under such con- 

 ditions. The larger proportion of plants appearing from healthy seed 

 than from affected seed under unfavorable conditions for germination 

 is due to the attack of the new tissues by the anthracnose fungus and 

 sometimes by other fungi associated with it. Edgerton ( 1910 : 36) obtained 

 a much lower percentage of germination from anthracnose-spotted seed 

 planted in unsterilized soil than from that planted in soil that had been 

 sterilized, due to rot organisms in the unsterilized soil which attacked 

 such seed. He says, however, that in the latter case the great majority 

 of plants appearing were destroyed by anthracnose, while in the former 

 there was greater freedom from the disease, indicating to him, as did other 

 trials and observations, that rot organisms of the soil, especially a certain 

 Fusarium commonly associated with anthracnose spots on seed after 

 planting, will in Louisiana greatly reduce the severity of the anthracnose. 



It appears that when a diseased seed is placed in a fairly moist situation, 

 the threads of the fungus, theretofore dormant, renew their activity, 

 extending into healthy cells beyond and forming spore-bearing conidio- 

 phores at the surface of the lesion. These conidiophores appear first 

 as small black pimples in the lesion, from which spores issue in small, 



