514 



3. This grass grows only iu cultivated land ; it best prospers in the warmest fourth 

 of the year; during this time two full crops may be gathered. Its luxuriant growth 

 without much root subdues other grasses and some weeds, with the result of leavin"- 

 the ground iu an ameliorated condition. ° 



4. This grass little intprferes with cultivation of a corn-crop ; and, after the corn is 

 worked enough, this grass matures its heavy crop simultaneously with maturity of 

 the corn ; and, the corn being gathered, both the corn-stalks and the grass together 

 may be turned under the surface iu preparation for an autumn, winter, and spring crop 

 of some other kind of grass or small grain. 



5. Without a corn-crop this grass may give two cuttings in the summer, and also 

 give full opportunity for using the same ground in one or more other crops during the 

 autumn, winter, and spring. 



6. Diligent inquiry has not obtained information that this kind of grass has yet 

 appeared either out of Texas or within it eastward of the Colorado Valley, leaving an 

 impression that such grass cannot be successfully propagated, except in such jT cli- 

 mate as obtains iu Southwestern Texas. 



This ffrass is a species of Panicum, probably P. fasciculatum, Svrartz, 

 which grows in Mexico aud South America. Jt has likewise been sent 

 from Colorado, where it has probably been introduced. We hope that 

 those farmers living in the Southwestern States will give this grass 

 a trial, as it seems to promise well for that section. 



MICROSCOPIC OBSERVATION. 



By Thomas Taylor, MiCROSConsT. 



Black-knot of plum and cherry trees— (Continued.) — Having 

 recently received from a gentleman of New Jersey, Mr. Abram McMur- 

 trie, some excellent specimens of black-koot taken from plum and cherry 

 trees of different ages, I resumed my investigations of that disease with 

 very satisfactory results. A portion of the fungus being removed from 

 a specimen of the black-knot which had grown on a plum-tree about 

 seven yeavs old, and being submitted to an examination by the micro- 

 scope, at a very low power, exhibited forms of fruit (perithecia) as seen 

 at 8. When viewed in section by a higher power, it appears as at 9 j 

 and in top view as at 10, showing an indentation in each perithecium. 



When a perfect specimen, as seen at 9 or 10, is submitted to the action 

 of nitro-muriatic acid for about thirty minutes, a slight decomposition 

 of the acid takes place, indicating that the resinous or oily matter of 

 the perithecium becomes oxidized. These strong mineral acids have no 

 destructive action on the organic structure of the perithecium, although 

 they have the property of bleaching it in some degree, thus rendering 

 it translucent, and making its cellular structure visible. If ammonia is 

 added in drops to the specimens, after having been treated with acids, 

 their albumenoids become pliable. This process is especially valuable 

 when applied to matured and dry specimens ; 6 represents a very highly 

 magnified specimen of a perithecium, a part of which is in section and 

 represents the internal arrangement of the asci and sporidia in them. 

 From my recent experiments on black-knot I am now able to demonstrate 

 its structure. If a perfect iierithecium which has been treated with acid 

 and ammonia, as previously described, is gently bruised on a microscopic 

 glass slide, by any of the well-known modes, the asci containing the 

 true sporidia will escape, and frequently the sporidia will be seen in 

 profusion on the glass. I have counted as many as ten sporidia in one 

 ascus. When the perithecium is very inliable, and the interior mass of 



