OF THE FAKM AND GARDEN. 125 



the sheath, as is supposed to have been done in the en- 

 graving, they become at once very conspicuous objects. 

 We have observed that the "infcernodes," as botanists 

 call them, or the spaces between the knots, in infested 

 straws are always much contracted in length, none out of 

 a lot of over fifty specimens examined by us exceeding 

 six niches in length, and many being reduced to only one 

 and a half inch. There were only three straws in this 

 lot of over fifty straws, where two Joint- worm galls were 



Fig. 86. THE JOINT-WORM (Isosoma hordei, Harris), 

 a, Galls at joints ; ft, Female Fly, enlarged, the lines showing the real size. 



found in the same straw; and in all those three cases 

 they were found in two adjoining internodes. In a very 

 few instances the galls were situated in the middle of the 

 internode, or even close to the upper knot, instead of be- 

 ing situated as usual above the lower knot. 



AMOUNT OF DAMAGE DONE BY THE JOINT-WOKM. 



The damage occasioned by the Joint-worm is, in cer- 

 tain seasons and in certain localities, ruinously great. 

 In the year 1851, through a large part of Virginia, ac- 

 cording to the Editor of the "Southern Planter," 



