154 EXPERDIEXT STATION. [Jan. 



iiekl and laboratory. The results of these experiments will be 

 diseussed later in the paper. 



Relation to Mosaic Disease. 

 It was at first thought that there might be some relation be- 

 tween the so-ealled " mosaic disease " and this, but from onr 

 observations we have been able to find only a superficial rela- 

 tionship, i.e., as regards the distortion of the leaf in its first 

 stages. Other investigators,^ as has been previously menti<med, 

 have prove(l ihat the '" mosaic disease " can be communicated 

 from one plant to another l)y inoculating a healthy plant with 

 the jnice of a diseased plant, and that the new growth subse- 

 quent to the inoculation will come diseased in nearly every case. 

 This is not so in the case of sprout growth, however, as in no 

 instance were we able to bring about a diseased condition of 

 nornuil plants by inoculating them with juice taken from dis- 

 eased leaves. As it was impossible to carry on these inocula- 

 tion ex])erinu'nts in the laboratory, the work was done in the 

 field, and observations taken from time to time. 



Experiments in iNocrLATioN. 

 In order to ]u-ove that, unlike mosaic disease, this malfor- 

 mation could not l)e communicated from a diseased sprout to a 

 healthy one, the following experiments were made. Two series 

 of ten inoculations each were made; in one case diseased tissue 

 was inserted at the base of the terminal bud of normal, healthy 

 sprouts; in the second series the terminal buds of healthy 

 S])routs were inoculated with the filtered juice from diseased 

 ])lants. In all cases a healthy plant was inoculated with the 

 tissue or juice of a malformed plant of the same kind, i.e.. a 

 maple was inoculated with juice from a diseased nuiple shoot, 

 etc. In not one case could we find that the trouble was either 

 contagious or infectious in character. The results of these inoc- 

 ulations are given in Table T., and from these results it is evi- 

 (hmt that the disease cannot be communicated from one ]dant 

 to another. 



> A. F. Woo.ls, U. S. Dept. Agr., R>ir. Plfinl Ind., Bui. No. 18. 



