194 



AGRICULTURAL REPORT. 



ou the ends of the branches arc compound, and when moistened le- 

 solve themselves instantlj' into separate sections, (2.) AYhen the njold 

 is matured, view by a power 

 of about 75 diameters, it ap- 

 pears double-fruited, as at 5 

 and 6. It is believed by the 

 farmers at Swampscott that 

 dry weather favors the 

 growth of the white mold, 

 but that moist and rainy 

 •weather favors the growth 

 of the black fungus, or rot, 

 which is seen mostly on the 

 bulb of the onion. When 

 the black spores arc viewed 

 by a power of about one- 

 eighth, they appear of a ro- 

 sette form, (3,) each resem- 

 bling a combination of cells, 

 encircling a common center. 

 Figure 30 represents at 7 a 

 highly magnified view of a 

 portion of the leaf of a mil- 

 dewed onion; 8, a chain of elliptical spores, which grow in great 

 profusion over it, when the leaf is kept in a moist condition for a 

 few days ; shows stomates of the leaf from which thread-like mold, 

 mycelium, is seen to proceed, proving that the fujigus has ramifications 

 under the epidermis, and doubtless through the intercellular spaces, if 

 not through the cellular substance itself, from which the fungoid threads 

 draw nourishment for the support of their fruit, &c. I subjected the 

 black spores (3) to the action of concentrated nitric, uitro muriatic, and 

 sulphuric acids, caustic, ijotash, and lime, for twenty-four hours, without 

 effecting any change in the structure. When immersed eight days in nitro- 

 muriatic acid, the spores become slightly bleached, and appear as at 4. 

 When immersed in heavy oil of tar, which contains a large portion of 

 carbolic acid, their structure is materially changed. 



In an address delivered by Mr. W^are before the Essex Agricultural So- 

 ciety, at Kewburj'port, September 29,1869, he said that "^ The onion- 

 blight and smut is at times very destructive to the onion crop, turning 

 the most promising fields in a few days to scenes of desolation, which 

 is caused, in my opinion, by a parasitic plant, growing upon and con- 

 suming the vitality of the onion. The onion-smut so impregnates the 

 land with its spores, as to render it unsafe to plant onions for several 

 years on land thus affected. White blight comes upon the crop at the 

 I)eriod of its most vigorous growth, in a dry time, showing its effect per- 

 haps in a small spot at first, but, in case the dry atmosphere continues, 

 rapidly spreading over the whole field. T^'O or t^hree days give sufiicient 

 time to stop entirely all future growthof the crop, unless a change iu the 

 weather occurs unfavorable to the growth of the parasite." 



When an onion affected with fungus is placed in a vessel with, a few- 

 drops of water and exposed to a temperature of about 75"^, its decay is 

 liastened very materially, but apparently more from the presence of in- 

 fusorial life than from the parasitic fungi. The latter seem to prepare 

 the way for the development of a species of angulula, which appears in 

 great numbers, also, monads, water-mites, vibrious and bacteria, by 

 breaking up the proximate elements. These being destroyed, or changed 



