169 



cycle so much the more cjuickly. The beginnings of the disease must be 

 sought in a rather early stage of the fruit's development. I often found in 

 diseased cell groups, recognizable by browned and corked membranes, many 

 grains deposited on the cell wall. These slowly colored blue with iodine 

 and therefore must be spoken of as starch. Some of them showed a warped 

 seam which remained whitish. Further, a splitting of the browned tissue is 

 observed often in the tough fleshed early apple, varieties which are most 

 inclined to become specked. These splits are explained by the fact that when 



transparent in water until it can no longer be recognized. No actual dissolving- of 

 the substance has been observed. If fresh sections are laid first in water, cloudy 

 drops do not appear, from which it may be concluded that the substance is taken 

 up by the water. Indeed, in several cases, it was observed (in Reinettes) that if 

 the drops had disappeared after a rapid temporary action of the water there was 

 left a fine grained residue. With the addition of glycerin the solid grains either 

 form drops or separate filament-like pouches. Per- 

 haps it is only these grains which, imbedded in the 

 drops and the remaining, above-mentioned forms 

 claimed to be different aggregate conditions of some 

 ground substance, swell up to polyp-like radiations. It 

 is seen especially in the drops which are enlarged to 

 a thick-walled vesicle by a vacuole that only some 

 places may be elongated like pouches or chains of 

 beads which in individual cases can reach the wall 

 layer and thus transverse the cell as knotted bands. 

 With the continued slow swelling in glycerin the 

 figures change constantly whereby the substance, 

 which becomes more and more doughy, more weakly 

 refractive and stringy, shows an attempt to return to 

 the drop form. Either some of the chief arms of the 

 above represented polyp-figure take up more and 

 more substance and become broad bands which finally 

 draw together into spherical drops, or separate beads 

 of the chain show a stronger growth with a constant 

 increase in size and decrease in refractive power, 

 whereby the smaller spherical links of the chain and 

 the thread-Ike substance possibly connecting them 

 becomes more slender, finaUy tearing- apart and be- 

 coming drawn into the larger drops. In most pro- 

 nounced cases these drops were recognizable after 96 

 hours, but later could no longer be found nor pro- 

 duced again by reagents. 



The reason that I place the substance mentioned 

 in the list of sugars, or between sugars and ferments, 

 is their occurrence in the same cells, which contain 

 large, strongly refractive drops capable of being 

 drawn together by glycerin, or separated by alcohol and 

 showing a copper reaction into which it seems to me 



pass over the small, above-mentioned drop forms. The large syrup drops which 

 may be drawn together in certain parts of the cytoplasmic sac by glycerin and 

 which gradually disappear again, may be partially fixed by the use of the potassium 

 bichromat since a persistent brown -grained precipitate is formed. In pears I found 

 this phenomenon after the action of dilute sulfuric acid on the glycerin preparation 

 in which the walls of the stone cells became the color of wine. Ferric chlorid gives 

 no special color reaction. If a piece of caustic potash is put in the glycerin prepar- 

 ation the syrup balls color an intense yellow and the remaining cell content a 

 lighter yellow. Chemically pure grape sugar behaves similarly but, dissolved in 

 pure water, it gives only a weakly yellow liquid. The addition of calcium chlorid 

 or calcium nitrate will hold the drops in form somewhat longer. They then retain 

 their strong refractive power from 2 to 4 days. With the use of silver nitrate a 

 brown grained precipitate is produced in many syrup balls, which consists either of 

 many very small grain bodies or less numerous larger tuber-like ones. A part of 

 the drops disappear without giving any precipitate. 



It seems to me that we are concerned here with an extremely easily changed 

 substance, easily soluble in water and alcohol, but less soluble in glycerin, which 

 occurs in the same cell in different transitional stages, thus bowing different re- 

 actions Even exposure to the air brings about a change, since an apple, which 

 shows a quantity of drops on its freshly cut surface, does not show any drops on 

 this same cut surface after a few hours when acted upon by glycerin, and these may 

 only be found again deeper in the tissue. 



Fig. 18. Parenchyma cell 

 from the flesh of a ripe 

 apple after treatment with 

 undiluted glycerin. (Orig.) 



