PLANT GROWTH. 



443 



carried out by Professor Maynard, who to-day reports these 

 trees in a vigorous condition. Not feeling satisfied with a 

 mere assumption based on a presumed analogy of circum- 

 stances, during the last summer 1 invited Professor Penhal- 

 low to study the condition of the cellular tissue in branches 

 collected on the 11th of November, 1881, from trees thor- 

 oughly diseased, and also from trees which were once dis- 

 eased and are to-day in good healthy condition. For myself 

 I reserved the analysis of the mineral constituents of a lot of 

 branches from the same trees, collected the same day. In 

 connection with these analyses I also made the analyses of 

 the mineral constituents of the ripe and healthy (entire) 

 early Crawford Peach, and that of the entire, prematurely 

 ripened, diseased fruit. The following statement contains 

 my results : — 



Ferric oxide. Fe*0', . 

 Calcium oxide, Ca O, 

 Magnesium oxide, Mg O, 

 Phosphoric acid, F*0*, 

 Potassium oxide, K^O, 



Fruit. 



Crawford's Early Peach. 



Healthy. 



.58 per cent. 



2.64 



6.29 

 16.02 

 74.16 



Fruit. 



Crawford's Early Peach. 



Diseased. 



.46 per cent. 



4.68 



5.49 

 18.07 

 71.30 



100.00 



100.00 



The above analytical results show a remarkable difference 

 in the composition of the mineral constituents of the healthy 

 and the diseased plant. The differences in both cases are 

 most remarkable as far as potash and lime arc concerned. 

 The difference is more conspicuous in the branches than in 

 the fruit. The diseased objects contain less potash and 

 more lime than the healthy ones. 



The subsequent statement contains a summary of Profes- 

 sor Penhal low's results : — 



