31 



probably to the relatively small amoiiTit of lime in the reserve store of 

 the seeds. 



Palladiii ^ placed etiolated leaves of Vicia faba on the surface of dis- 

 tilled water, on a 10 per cent cane-sugar solution, and on solutions of 0.3 

 per cent calcium nitrate with and without the addition of cane sugar, 

 but a noticeable growth was observed only where both sugar and cal- 

 cium nitrate were present. The same author^ has found that etiolated 

 leaves of Yicia faba contain less lime than do green leaves. His analysis 

 showed that there were contained in 1,000 parts of green leaves 13.3 

 parts of lime, but in 1,000 parts of etiolated leaves only 2.6 parts of 

 lime. The former yielded 10.3 per cent of ash, the latter 7.54 per cent. 

 Stoklasa found in diseased leaves of the sugar beet less than half the 

 amount of lime present in healthy leaves of this plant. 



Church's investigations^ with albino leaves demonstrated that the 

 composition of their ash is very different from the ash of healthy leaves, 

 as the potassa is considerably increased in the white leaves, while on 

 the contrary the lime is more abundant in the green leaves. It is to 

 be regretted, however, that the author did not determine separately the 

 amount of lime present as oxalate and as carbonate and that portion of 

 the lime belonging to the organized matter itself, calculating the results 

 for equal surfaces in both cases. It is also very characteristic that the 

 lime content of the phanerogamic parasite Cuscuta, which forms no 

 chloroplasts in the full-grown state, amounts to only 2 per cent in the 

 ash, while the clover, its host, is very rich in lime. 



Another interesting case, showing a decrease in lime content in dis- 

 eased leaves, was observed by Dr. Erwin F. Smith in his studies of the 

 peach yellows. He gives the percentage of lime in the ash of the 

 healthy leaves, according to analyses made by Mr. N. E. Knorr, as 

 40.58, aud in the diseased leaves as only 23.88.* According to a later 

 analysis, made by Dr. Eastwood at Dr. Smith's request, the ash content 

 of healthy twigs of one season's growth is given as 2.10 to 2.58 per cent 

 and that of diseased twigs as only 1.6 per cent, and of healthy twigs 

 from another orchard as 1.4 per cent and of diseased twigs as only 1 ])er 

 cent.^ In these cases the amount of lime was also less in the diseased 



iBer. d. Deut. Bot. Ges., 1891, p. 230. 



nbicl, Vol. X, p. 179. 



•■^Jour. Chem. Soc, 1878 aud 1886. The investigations were made with Quercus 

 rubra bearing some albino branches, and also with albino leaves of Plectogyne varie- 

 gata and of Redera helix. 



-* Smith, Erwin F., Bull. No. 4, Division of Botany, U. S. Dept. of Agr. 



•'•Smith, Erwin F., Bull. No. 4, Division of Vegetable Physiology and Pathology, 

 U. S. Dept. of Agr. 



