APPENDIX. 169 



[G-] 

 The Grain-Worm, [Vibrio Tritici.) 



Extract from an article in the Penny Magazine No. 87, for 1838, on 

 the subject of the Grain-Worm, (Vibrio Tritici.) 



Mr. Bauer, the naturalist says, " I have been enabled to ascertain 

 many important facts, respecting the nature and properties of the mi- 

 nute animals engendering this disease. These experiments establish 

 the fact, that the white fibrous substances, within the cavities of the 

 distorted grains, consist of real organized animals endowed with the 

 extraordinary property of having their power of motion suspended for 

 a considerable length of time, and of having it again restored by the 

 mere application of water." 



He then goes on to detail some experiments, to show how these 

 worms were propagated, and how he succeeded in inoculating sound 

 grains with them, which I have not room to extract. He adds : 



" The fact that at such an early stage of the vegetation of these in- 

 oculated seed-grains, such large worms were found, confirms my first 

 supposition, that it requires several generations of these worms to 

 introduce their eggs into the young germens; the large worms found 

 in the substance of the young stem, were undoubtedly some of the 

 original worms, with which the seed-corn was inoculated; for they 

 were on the point of laying their eggs in that stage ; and these eggs 

 being propelled by the rising sap a stage further, then come to maturity, 

 and again lay their eggs, and thus progressively reach the elementary 

 substance of the ear, where they are finally deposited in the then form- 

 ing germens, the whole probably requiring three or four such repro- 

 ductions." 



" My experiments for resuscitating the grain-worms, I have repeated 

 almost every succeeding year to this day, and always with the same 

 success ; but I find that the longer the specimens are kept dry, the 

 grains require to lay in water a greater length of time before the 

 worms will recover; and that at every repetition of an experiment, a 

 smaller number of worms recover their motion; and that after the 

 same specimens (the produce of the grains inoculated in 1807,) had 

 been kept dry six years and one month, the worms were all really dead ; 

 this period is the longest, which I have as yet ascertained, that these 

 worms can retain their reviviscent quality. That this disease is con- 

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