382 Journal of Agriculture , 'Victoria. [10 June, 191 i. 



No. I showed a depressed area of about three-quarters of an inch on 

 the third day, and on the fourteenth day this had increased to fully one 

 inch in diameter, but without any noticeable discolouration, and on the 

 margin a few tufts of the fructification appeared. At the end of the 

 experiment, the tomato became soft and rotten, and the diseased patch 

 was overgrown with Fusarium. 



No. 2 was still firm and showed no trace of disease. 



No. 3 showed a small depressed area at infection point in three days, 

 and on the ninth day the slightly discoloured and softened area was about 

 \\ inch in circumference, and distinctly marked off from the sound 

 tissue. Tufts of sporangia had burst through the skin over the discoloured 

 area, and even beyond it. At the end of the experiment, the specimen 

 was completely rotten. 



No. 4 was similar to the preceding, and the origin of the spores from 

 the potato did not seem to affect the result. It was completely rotten and 

 ccvered with a thick felt of Fusarium. 



No. 5. — ^The potato remained quite firm and free from disease. 



No. 6. — There was no sign of infection on the third day, but on the 

 ninth day there was slight discolouration over a circular area of about 

 half-an-inch in diameter, and tufts of sporangia were seen bursting through 

 the lenticels, even beyond the discoloured portion. At the end, the entire 

 potato was invaded by the fungus, and tufts of sporangia were produced 

 all over the surface. 



No. 7. — This specimen showed discolouration on the ninth day over 

 an area of about 2 inches in diameter, and the fructification had burst 

 through over and beyond this. At the end, the infection had extended 

 over three- fourths of the area of the potato, and there were two strong 

 apparently healthy shoots and a few smaller ones at the crown end. This 

 was considered a very suitable sample for testing the assertion that the 

 produce of a diseased tuber is not diseased, and it has been planted whole. 



No. 8 was similar to the preceding up till the ninth day, and both 

 showed a slight discolouration on the third day after infection. At the end, 

 infection extended all over and tufts of sporangia were produced very 

 generally over the entire surface. 



It has now been conclusively shown that tomatoes and potatoes are 

 mutually infective and that, even with the tough skin unbroken, spores 

 falling upon them when moist, can produce infection, and a fresh crop of 

 spores may appear within nine days. 



A diseased tomato, like a diseased potato, may naturally produce spores 

 on the unbroken surface while still attached to the parent plant, the fungus 

 filaments protruding through the skin in both cases. But the tomato differs 

 in producing spores internally as well, for the filaments of the fungus 

 ramifying in the pulp bear spores freely in the cavities of the fruit 

 containing the seeds. 



It is evidently bad policy to plant tomatoes and potatoes side by side, 

 as is often done in our coastal districts, for there is always a risk of one 

 infecting the other, and consequently both crops may suffer. Further, 

 the tomatoes growing in the winter have been known to be affected with 

 blight, and thus the spores may be carried to the young potato crop, and 

 from the potato to the tomato for one-half of the year at least ; until the 

 dry heat of summer arrives to hold them in check. 



