378 



HENDERSON'S HANDBOOK OF PLANTS. 



MEL 



Melliferous. Honey-bearing. 

 Membrane. A delicate pellicle of homoge- 

 neous tissue. Also, a very thin layer of 

 cellular tissue. 



Meshes. The openings in any tissue. 

 Midrib. The large vein extending along 

 the middle of a leaf, from its petiole 

 nearly or quite to the other end. 

 Mildew. The term used for the parasitical 

 fungus so common to vegetation, both 

 under glass and in the open air. Like 

 nearly all other parasites hurtful to 

 plants, it seems to us that Mildew only 

 attacks plants when, from some cause or 

 other, they are in an abnormal state. For 

 instance, we find that if some varieties of 

 Hoses and Grape Vines, either under glass 

 or in the open air, are exposed to exces- ! 

 sive drought, so as to enfeeble the leaf j 

 action, or if exposed to a sudden change 

 of temperature, they are almost certain 

 to be attacked with Mildew. Many years 

 ago, in our green-houses at Jersey City, 

 N. J., we had a. marked instance well illus- 

 trating this belief. We had a Hose house, 

 on which the sashes had been slid down 

 for ventilation; it came up suddenly cold, 

 and before the green-house could be 

 closed, some six or eight square spaces of 

 3x3 feet, where the sashes had been let 

 down, were frozen so severely that the 

 young shoots of the Roses hung down, 

 and we thought they were ruined. The 

 next morning, however, they appeared 

 all right; but in a few days after Mildew 

 appeared in the square space (3x3 feet) 

 with the lines nearly as closely defined as 

 if struck out with a rule, the other por- 

 tions of the Rose house being entirely 

 free from it. Now we reason from this 

 incident, and others nearly as marked, 

 that spores or germs of mildew are near- 

 ly always present, floating in the atmos- 



MIL 



phere, and that when a congenial soil, so 

 to speak, is formed by a relaxed condition 

 of the plant, the floating germ is sown on 

 the enfeebled leaves, and the parasite 

 starts into the low organic life known as 

 Mildew. Fortunately, we have a rarely- 

 failing antidote against Mildew. Sulphur, 

 applied in various forms, is almost a cer- 

 tain specific. For Grape Vines, Roses, or 

 other plants affected by Mildew outdoors, 

 the flowers of sulphur applied by the 

 sulphur bellows, when used in the early 

 stage of the attack, will at once check it; 

 but when Mildew attacks Roses or Grape 

 Vines under glass in winter, the best plan 

 is to paint the hot water pipes with a wash 

 of sulphur and lime or sulphur and Gua- 

 no (the Guano or lime is only used to 

 make the sulphur stick to the pipes) 

 every eight or ten days. The fumes of 

 the sulphur, evolved by the heated water 

 in the pipes, (about 200 degrees,) is cer- 

 tain destruction to the germ producing 

 Mildew. We find it also valuable, when 

 so applied, in preventing the ' ' fungus of 

 the cutting bench," often so annoying 

 to the propagator. When flues are used 

 instead of hot-water pipes, the sulphur 

 wash may be used on them; but care 

 must be taken that it is only on the end 

 of the flues farthest from the furnace, as, 

 if much hotter than 200 degrees, it will 

 injure the leaves; but no harm can ever 

 ensue from its use on the hot- water pipes 

 or on the smoke flue, if not hotter than 200 

 degrees. At seasons when no fires are used, 

 the following preparation will usually be 

 found a prompt remedy against Mildew: 

 take six pounds each of flowers of sul- 

 phur and lump lime, put together and 

 slake the lime, adding ten gallons of 

 water. Boil all together until it is re- 

 duced to four gallons; allow the liquid 



