112 



ON THE PROPAGATION OF BUNT. 



In a month from the sowing of the wheat, the fecula of the 

 grains being then nearly absorbed, it was difficult to find any 

 spores, and no further developement of mycelium, directly from 

 the spores, had taken place. 



The first bunted ear appeared four months from the time of 

 sowing, and while every impregnated plant produced bunted 

 ears, not a bunted grain appeared on the plants which sprang 

 from uninfected seed. 



The experiments were repeated with precisely the same re- 

 sults. In a single instance the parasite was developed on the 

 tip of the tube protruded from the germinating bunt-spore. It 

 should seem then, as far as may be concluded from the observa- 

 tions noted above, which I am ready to confess should have been 

 more varied to lead to any certain result, that a penetration of 

 the mycelium directly protruded from the spores of fungi is not 

 always necessary for the developement of the fungus, but it is 

 probable that the grumous contents of the spores are imbibed by 

 the plant which is destined to be the prey of the parasite, and 

 that these, circulating with the juices, carry the principle of 

 disease to every part, and under favourable circumstances are 

 capable of reproducing the parasite. 



To establish a point of such delicacy would require ample 

 leisure, and very varied observation ; but there are few subjects 

 more likely to reward the observer, either directly or indirectly, 

 with new and valuable results. 



Should it prove true, there would no longer be any surprise 

 how a disease originating in the leaves might be propagated 

 through the stem to the tuber, or the contrary, and Martius' or 

 Morren's notions of contagion would no longer be regarded as 

 mere reveries of fancy. It is indeed opposed to the general 

 notion, that no reproduction takes place except by the separation 

 of a cell from the parent stock ; but, as knowledge increases, too 

 many of our most favourite and general notions are overthrown 

 to justify us in being diverted from research, through the mere 

 stumbling block of preconceived opinions. 



There is another direction to which observations also may be 

 led by the subject. The production of the parasite on the spores 

 of bunt was constant in my experiments, and was repeated at 

 Bristol and Clifton under the eyes of Mr. Thwaites and Mr. 

 Broome, to whom I had communicated bunted grains of wheat, 

 for the express purpose of seeing whether the same circum- 

 stances would take place at a distance. I was at first inclined 

 to think that it had something to do with the reproduction of 

 the bunt ; and it is quite possible that in plants, as well as in the 

 lower animals, there may be an alternation of generations. This 

 is, however, merely thrown out as a hint which may be followed 



