J)ISEA^ES OF WHEAT. Q^f 



water. One of the grains was tilled with a brownish sub- 

 stance fall of perforations, from which issued small worms 

 discernible by the naked eye. They continued to live in 

 water, and upon examination corresponded in all respecta 

 with those seen by Roffredi in the plants which he raised. 

 Since that time I have opened several recent grains, which 

 contained a few of this sort, as well as the anguillulae. They 

 were more than twice the diameter, and about the same 

 length. Perhaps the grains which vegetated with Roffredi 

 might not have been so much diseased as those I sowed, for 

 that some are only partially infected I accidentally disco- 

 vered. The first parcel I procured were only blackish on 

 one side, and contained very few animalcula. The rest of 

 their contents a])peared similar to that of sound wheat, ^^t he think* 

 There can therefore be little doubt, that had they been it possible and 

 sown, they would have come up. However that may be, it 

 is certain they do vegetate, for I have since that examined 

 several roots of this diseased wheat, and frequently found 

 the grain from which they sprung to be similar to that in the 

 «ar. 



None of the anguillulee 1 examined exceeded the two hun- Examination 

 dredth part of an inch in diameter, and they were in general oftheanguillu- 

 about twenty-six times that length. When viewed with a croscope. 

 hand magnifier they appear of a silvery white, but when 

 placed in the microscope under a highly magnifying power, 

 they are of a bright chesnut colour. A row of transparent 

 globules, placed at regular distances, run down each side of 

 the body till within a third of the extremities. Last winter They are lonj^ 

 I preserved an immense number of them three months in a ^^^^^> 

 watch glass, by frequently adding fresh water to them. 

 They did not increase in size, neither were they changed in 

 any respect. If they are not endowed with sight, they are and affected by 

 at least very much affected by light. When placed in the ^'Sl^'* 

 rays of the sun, or in the light of a candle, in a minute or 

 two they run together into one or several bunches or knots, 

 and continue so for some time. This effect is most distinctly 

 viewed by means of the solar microscope. When placed in 

 that instrument, they are seen floating from every part of 

 the fluid to form themselves into an apparently inextricable 



bunch, 



