68o 



circumstance and lays emphasis on the fact that the slime cells are fewer 

 in the non-pigmented parts of plants which bear the mucilage cells (Ulmus, 

 Crataegus). On the other hand, the content of tannin in the white parts is 

 usually proved to be greater. Starch is found rarely but, according to 

 Timpe, in a sugar solution is often formed more abundantly by the non- 

 pigmented places than by the green ones. Monocotyledons store up no 

 starch in a sugar solution. 



It is stated by other authors that the pure white places contain no starch 

 since assimilation does not take place there. These apparent contradictions 

 are explained by the transitional stages to a golden yellow color which, 

 indeed, contain no chlorophyll but have zanthophyll and carotin and elim- 

 inate oxygen in the light (like etiolated leaves)*. 



An interesting fact is that in many plants a lack of pigmentation may 

 be communicated to the stock by grafting. Meyer^ reported experiments 

 of this kind with positive results as early as 1700-1710 with Jasminum 

 officinale. "If a branch of Jasminum with variegated leaves is grafted on 

 the healthy trunk of the same Jasminum, the other branches above and 

 below the scion likewise bear variegated leaves." Later Lindemuth^ and 

 recently Baur^ have studied the question especially. Baur has advanced the 

 theory that the yellow forms may be considered to be sport varieties, or 

 mutations, which in part persist in the seed. The pure white, however, 

 should be distinguished from these as examples diseased by infection. At 

 any rate, the infecting body may be no living creature, but an unknown 

 material something, a virus which can increase in amount within the dis- 

 eased plant. This virus can be a metabolic product of the diseased plant 

 which is able to infect the young chloroplasts in such a way that they cannot 

 develop tc normal organs, but to malformations in which then the same 

 virus is formed anew. However, it may be a metabolic product of the 

 diseased plant which, in a certain sense, has the capacity for growth, i, e., 

 can split off substances from other compounds identical with it, or can 

 synthetically construct new substances of this kind*. 



This line of thought has already been expressed in a more precise form 

 by Pantanelli% and later supplemented. He sa3^s^', "the albinism is not an 

 infectious disease, but a constitutional one, the first sign of which occurs as 

 an abnormal accumulation of destructive and primarily oxidizing enzymes." 

 "The substances, causing the destruction, spread through the leptome. 



* Kohl, loc. cit. 



1 Meyen, F. J. F., Pflanzenpathologie, Berlin, 1841, p. 288. 



- Lindemuth Vegetative BastarderzeuRung durch Impfung-. Landwirtschaftl. 

 Jahrbiicher 1878, Part 6. Gartenflora 1901, 1902, 1904. 



3 Baur, Erwin, Zur Aetiologie der infektiosen Panachierung-. Ber. d. Deutsch. 

 Bot. Ges. 1904, Vol. XII, p. 453. Further statements on the infectious chlorosis of 

 the Malvaceae and other simila. phenomena in Ligustrum and Laburnum. Ber. d. 

 Deutsch. Bot. Ges. 1906, Part 8, p. 416. 



* Baur, E., tJber die infekti()se Chl.orose der Malvaceen. Sitzungsber. d. Kgl. 

 Preuss. Akad. d. Wiss. January 11th, 1906. 



5 Pantanelli. E., Studii su I'albinismo nel regno vegetale. Malpighia. Vol. 

 XV-XIX (1902-5). 



6 Pantanelli, E., tJber Albinismus in Pflanzenroich. Zeitschr. f. Pflanzenkrank- 

 heiten 1905, p. 1. 



