i68 



on the trees and was kei)t from autumn until the next summer in a cool, 

 light cellar, in order to let the fruit mature as slowly as possible. In this it 

 was proved that some fruit with an absolute uninjured wax coating was still 

 sound in August, but absolutely insipid in taste and of a mealy consistency'. 



BiTTKR Pit. 



In the flesh of fruit, especially of apples, brown, tough, scattered spots 

 are produced, which sometimes taste bitter. If these are found just beneath 

 the skin they become noticeable as somewhat depressed tough places, which, 

 at first paler in color, finally become brown. The phenomenon is most fre- 

 quent with porous soil in dry years, such as 1904. The firm fleshed varieties 

 suffer less. Although a fungus Spilocaea pomi Fr. is given by some in- 

 vestigators as the cause, I still would like to consider the phenomenon as the 

 result of a too rapid maturing in individual cell groups in the flesh. In each 

 fruit the tissue of the flesh seems unequally filled with reserve substances. 

 If premature dr}mess of the soil prevents the accumulation of the proper 

 amount of organic material for the complete maturity of the fruit, dilTerent 

 tissues will remain especially poor in contents and actually complete their life 



1 In mealy fruits, as well as in thuse normally juicy, the state of ripeness is 

 characterized by the appearance of peculiar .substance groups becoming visible 

 immediately after the sections have been put in undiluted glycerin. 



The adjacent figure shows a cell from an apple (Gloria mundi) when the section 

 had been placed immediately in glycerin. The delicate plasmatic primordial utricle 

 which had been contracted into folds is partially omitted in the drawing. The 

 content is pushed together more or less. Also the very large vacuole at once notice- 

 able in most cells, usually lying in one corner (which I would like to call an acid 

 vacuole), is omitted in the illustration so that the substances appearing with the 

 glycerin reaction may be more clearly apparent. Emphasis should be laid upon 

 the fact that all cells do not show this response. The outer flesh of ripe apples, 

 pears and peaches reacts especially well. The investigations indicate that a 

 substance closely related to sugar is present in the cells in various transitional 

 forms. This substance is found between isolated larger vacuoles or the numerous 

 very small ones; it might be imbedded in the cytoplasm or be free in the cell sap, 

 either as separate cloudy drops or in rectilinear masses which, from their appear- 

 ance, may be dough-like in consistency. Often they are found in more strongly 

 refractive and solid forms as tuberous, warty, irregular growths. This most solid 

 state appears also in the form of very small, sandy grains imbedded in the cell wall, 

 attention to which is first called when they swell up to drops or (by forming 

 vacuoles) to small bubbles in the glycerin. All three forms have a capacity for 

 swelling in glycerin. When observed under water, the drops become indistinct and 

 disappear, but in extracted apple juice they remain visible and may be distinguished 

 from the different vacuoles. The radiating middle structure of the figure shows the 

 most marked results of the swelling, while the doughy condition of the substance is 

 indicated by the shaded surface with curved outlines lying below this. The sur- 

 roundings represent the part of the cytoplasmic sack, which lies in the same plane 

 and which encloses the grains of coloring matter and two vacuoles. 



The process of swelling is the same in the three masses described above, but 

 occurs in different intensities. It appears most rapidly and furthest developed in the 

 drop form and decreases the firmer the substance becomes. With the addition of 

 water the drops disappear first, in their place there remains at times a finely ground 

 residue at the edge of the cytoplasm; somewhat later the doughy masses become 

 invisible and the dividing line formed through the cytoplasm becomes circular. The 

 polyp forms become slowly transpaient; the warty masses gray grained and 

 cloudy without dissolving entirely in one day. If, at the beginning of the entrance 

 of water, cloudy balls, generally lying along the walls imbedded between the 

 vacuoles, ai^ observed, there is frequently noticed a swelling of different groups of 

 cell contents beginning at the inside, which increases up to the formation of vac- 

 uoles. A similar phenomenon is found with glycerin where the process sets in more 

 slowly and the changed conditions are retained longer. By this process of swelling 

 of the substances imbedded in the cloudy drops, the inner part of those appears 

 at times filled by one or more vacuoles in such a way that an actual cloudy mass 

 occurs only as a slender ring enclosing the vacuoles. This becomes more and more 



