on 
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cially bad. In a short time he began to react. He had catarrh and cough. 
On account of his cough he was inclined to be in the open air less and less 
and to house himself more and more, the very things he ought not to do. 
When I pointed out these things he promptly changed his mode of life and 
the reaction ceased. He was again “healthy”. 
It is undoubtedly true that all now common weeds and pests and para- 
sites and diseases were restricted at one time to certain localities, from 
whence they have spread until they have become cosmopolitan. There are 
many data regarding first appearances. In our annual Proceedings, for 
instance, are a number of records for the first appearance of new plants 
and new animels, new in the sense of not having been found here before. 
The appearance of new diseases in the State is of course recorded in the 
medical journals, but imperfectly. The subject of the coming in of new 
pests and parasites and diseases is an important one and cannot be dis- 
missed with a few brief paragraphs. I should like to give at least one 
illust ‘ation relating to the common potato. 
The potato ‘was cartied from South America to Europe about the 
middle of the sixteenth century, and subsequently brought to our country, 
and now goes under the name of the Irish potato. Those of middle age can 
recall how, until in the seventies, the Colorado potato beetle was never seen 
in our potato fields. How this beetle came to us is an interesting story. 
On the dry western plains there grows a species of spiny Solanum 
(S. rostratum), a near relative of the potato (S. tuberosum). This plant 
has a parasite, the beetle now commonly known as the potato bug. The 
plant grows very sparingly and that means that the beetle also occurs 
sparingly. A little reasoning will show why. If the bugs became abun- 
dant and would completely consume their food plant then they themselves 
would perish for want of food. On the desert the plants are far apart and 
many escape the attacks of the bugs and ripen seed, or if a single bug 
reaches a plant it will not injure it enough to destroy it. 
Now when the common potato began its westward march it gradually 
reached the home of this beetle. The beetle found the new species more 
acceptable than the old and, since plants were close together, life conditions 
became easy and the potato beetle, now called the potato bug, at once in- 
creased enormously and traveled from one field to another, and in a short 
time overran the whole United States. I was surprised when in Germany 
to see the potato fields free from the potato bugs; authorities there are on 
