Vol. XXVII, 



igro 



J McA-LPiNE, Smuts of Australia. 13 



1. The most common mode is that in which the young seed- 

 lings are infected, as in oat smut. (Seedling infection.) 



2. Another way is where any young and growing portion of 

 the host-plant is capable of infection, as in the American corn 

 smut, which, however, is not known in Australia. (Local infec- 

 tion.) 



3. Infection may also take place through the flower, and the 

 mycelium or spawn of the fungus lies dormant in the ripe grain, 

 as in loose smut of wheat. (Flower infection.) 



4. Infection is also known to occur through the young shoots, 

 as in carnation smut. (Shoot infection.) 



As an illustration of how the mode of infection is determined, 

 I may take the case of the smut of maize, prevalent in Victoria. 

 It has not hitherto been known how the maize-plant w^as infected 

 with this smut, and to answer this question, I planted various 

 plots at the Horticultural Gardens, Burnley. The different 

 methods were tested by infecting the seed, the growing plants, 

 and the shoots which sprang up when the plant was cut close to 

 the ground. The result was that the seedling infection pro- 

 duced the smut, and now we are able to recommend methods of 

 treatment. 



In conclusion, there are a number of questions suggested by 

 the smuts, such as parasitism and immunity, toxins and antitoxins, 

 and the relations between host and parasite, which it would be 

 out of place to discuss here, but they indicate clearly that the 

 parasitism of the smuts is bound up with the question of parasitism 

 in general. The study of the smuts may therefore throw light 

 upon some of the great scientific problems of the present day, 

 and when they are regarded, not as isolated forms, but as links 

 in the great chain of existence, they may contribute important 

 data towards the establishment of a science of General Pathology. 

 I have recorded and described the smuts known in Australia in 

 this year of grace 1910, and you as field naturalists may extetid 

 our knowledge in this direction. One of your former presidents, 

 Mr. Barnard, remarked in his presidential address for 1907 : — 

 "In a new country, until your objects have been collected in 

 fairly large numbers, and dealt with from a systematic point of 

 view, it is difficult to see on what lines to investigate the steps in 

 their individual life-histories." I thoroughly endorse that remark, 

 and have simply endeavoured to translate it into practice. 



Although the name of smut is often used as a term of reproach 

 and associated with something that is disagreeable and often 

 evil-smelling, I can assure you, after a fairly long acquaintance 

 with them in their various phases, that they exhibit beautiful 

 adaptations to their environment, and that the black masses of 

 spores, when viewed under the microscope, reveal a beauty and a 

 symmetry which would delight the soul of the artist. 



