496 DISEASES 



to be one of this class, and is as interesting to the vege- 

 table pathologist as it is destructive to the orohardist. 

 The latest view o£ this particular form of disorder is 

 that of the unorganized ferment, which by causing cer- 

 tain chemical changes in the substances of the cells brings 

 about the peculiar and well marked malady of the "yel- 

 lows." If we start with the premise that there is a cer- 

 tain small amount of chemical ferment in all plants, it 

 is only necessary to have this increased to get the re- 

 sults in question; and how to prevent this augmentation 

 is the practical point at issue. This ferment in active 

 form might be communicated f ri.ni one plant to another 

 by budding or grafting, and. instead of introducing liv- 

 ing germs, it is a transmission of a gerraless ferment 

 like diastase, that is found in seeds, and does its ap- 

 pointed work as a solvent, in the period of germination. 

 There are other disorders that are called " CEdema," or 

 a dropsical form of disease. The tomato is subject to 

 this, and pelargoniums likewise. Tumors are formed, or 

 the leaves bear translucent dots along the veins. This 

 trouble is most apt to appear with greenhouse plants in 

 early spring, and may be favored by lack of sun- 

 shine, especially if the warm soil is wet and root action 

 is excessive. The remedy lies in furnishing, so far as 



DISPORUM 



possible, the conditions opposite to those above named. 



In general, it may be said that diseases which are 

 due to germs or to malnutrition show the disorder 

 more or less generally spread over the plant, rather than 

 confined to local areas. For example, if the foliage 

 shows a general wilting, it is evident that the trouble 

 lies farther back than the leaves themselves. If one 

 leaf begins to die all around the edge (as in Fig. 72G), it 

 is indication that the trouble is a cutting off of food 

 supply in the entire leaf; the trouble may be near the 

 base of the leaf, or farther back. After a time, the leaf 

 becomes dry and brittle, and the winds break it. In Fig. 

 727 it is evident that the trouble is in the whole branch. 

 Btron D. Hai.sted. 



DISHCLOTH GOUED. See Luffa. 



LiUAcea. Per- 

 our much-loved 

 iiii^iiished by an 



a .'apsule that 



. 'W: 



Pel 



nth 



ely cot date at base stigma S-cleft. 

 et 1/ broad and unequally rounded t 

 the base 



M^nziesu, Nicholson (P Menzie ii Don). More or 

 le^s woolly pubescent stem 2-J ft long forking, arch- 

 mg above Ivs ovate to ovate lam ( olate narrowly acu- 

 mraate or the lowe t acute e ile 2-3 in. long, often 

 resin dotted fls l~i greeni h from the topmost axils, 

 nodding 7-9 lines lon^ peditels puberulous; perianth 

 segments nearly erect acute 6-11 lines long; stamens 

 a third shorter anthers included lH-2 times shorter 

 than the filaments berry 3-fa seeded cells 1-2-seeded : 

 fr oblong obovate narrowed to a short beak. Calif. 



i Pcnanthnatiouandii 

 lanugindsum Nicholson 



jieuedge shaped at the base. 

 Wooll> pubescent: Ivs. ob- 

 inin ite peiiauth-segnients 



S-, pubescent stem 1-1 Htt higB, forking, 

 U tolia^e on the upper half Ivs ovate to oblong-lan- 

 latt acute or rarely acuminate 2-4 in long : pedicels 

 use perianth segments whitish slightly spreading, 



I re nai rowlr oblanceolate than in J) Memiesii, acute, 

 I I lint 1 ni, al out as lcn„ as the stamens: berry 



II 11 -I 1 1 tr broadly obovate, ob- 



II I [I It 1 ] [ ill Saskatchewan to 



\\ / ) tl J J if lamping. 

 Oreganum {P Oitgaua h Wats ) More or less 

 woolU pubescent Ivs o^ ate to oblong lanceolate, long- 

 acuminate perianth segments spreading, acute, nar- 

 I wtd below very distinctly net vemed 5-7 lines long, 

 1 11^ I or shorter than the stamens : fr. ovate, 

 iti 1 mewhat pubescent cells 1-2 seeded. Oreg. 

 I I I ih to B C 

 [ 1 1 II mt, kind tre nit abroad D Sohkeri, Nicholson 



II II k 1 B ker) Betore D. Oregannni in 

 ' short, usnally 



robust form of 



