128 



LOWER PLANTS, DISEASES, AND MEDICINE 



adapted to as wide an area as any few feeble efforts at public relief were 



cereal, in fact, far wider than wheat, undertaken, partly by the Church and 



This shift from cereals to potatoes was partly by the State, but they were in- 



particularly prominent HI Ireland; that's adequate and probably could never 



the reason why we often refer to a po- have been adequate to feed the whole 



tato as the Irish potato. Ireland was so population of Ireland, lire best they 



densely populated in the early part of could do was to stave off the evil day 



the 19th ccntur)- that the potato was a for a few people. The starvation 



godsend to them. The first thing any- showed first as dull headaches and 



body knew, Ireland had almost ceased bloated bellies; finally, the sufferer 



to grow cereal of any kind and was de- came under the spell of hallucinations 



pending almost exclusively on the po- and finally died from weakness. Terror 



^'^^^- and panic were common throughout 



Just about 100 years ago a new dis- the land and the ships sailing westward 



ease of potato appeared in central to the United States were packed to 



Europe. It had never been seen before, the gunwales with people rushing away 



It was a nasty disease; it made the from the famine that had encompassed 



leaves suddenly turn water-soaked, their homeland. 



slimy, rotten, and black. Tliat wasn't So much for a couple of plant dis- 



such a bad symptom except that the eases that altered history, 

 fungus that caused the disease spread 



from the leaves into the tubers and what causes disease 

 caused them to decay with a very 



curious and unusual sort of hard rot. In the fight with the fungi, we had 



Tlie disease, which we now know as to find out first that it was fungi that 



late blight, spread with lightning rapid- we were fighting. We had somehow to 



ity over Europe and appeared in Ire- discover what it was that caused plant 



land in 1844. We might describe its disease. This was not so easy. The an- 



catastrophic attack on Ireland in the cient man knew some of the causes of 



words of an eye witness. Father Mat- food destruction. He could see the 



thew, who says, "On July 27th I passed locusts that ate his wheat in the field 



from Cork to Dublin, and the doomed and the rats that ate his wheat in the 



plant bloomed in all the luxuriance of granar}'. But he could not see the 



an abundant harvest. Returning on fungus that was steahng the starch 



August 3rd, I beheld with sorrow mere from the grains and causing them to 



wastes of putrefying vegetation." shrivel and shrink. 



In the 7 days mentioned by Father We very glibly say these modem 



Matthew, the stage was set for a famine days that plant diseases are caused 



in which a quarter of a million people chiefly by fungi, and we all pretty well 



actually starved to death from slow understand that a fungus is a small, 



malnutrition and a million and a half chlorophyll-free thread that we can see 



emigrated, many of whom became Irish quite easily under the microscope. How 



policemen in the United States. Es- did we arrive at this simple-sounding 



sentially the entire potato crop of Ire- conclusion? 



land was wiped out. The people who First of all, what is a disease? Is dis- 



had been dependent upon potatoes to ease a condition? Some people would 



pay the rent and to carry them through say that it is. In that case, would you 



the winter suddenly found themselves say that fever is a disease? Well, niost 



without any potatoes, and they knew of us would say that fever is not a dis- 



that they faced a dreadful winter. A ease. Fever is a condition. When our 



