42 



Textbooks galore contain illustrations of the internal struc- 

 ture of apples. Unfortunately, such illustrations are too fre- 

 quently conventionalized to an extent that they present definite 

 and unnecessary inaccuracies. These are to be found, not only 

 in general science and elementary biology texts, but also in first 

 year botanies bearing distinguished authorship. 



The first illustration is taken from the latter source. Perhaps 

 the artist thought it necessary to meet the common desire for 

 balanced structure, and thus showed opposite locules where 

 such can not occur, unless abnormally. It would seem, however, 

 that there is no more reason for misrepresenting the internal 

 arrangements of apple carpels than there is for showing all twigs 

 with opposite leaves or scars. Such conventionalization, if 

 intentional, is contrary to the fundamental aim of teaching 

 accuracy of observation and representation, and, in any event, 

 the mistake hardly seems to offer any real advantage. 



A similar conflict between strict accuracy and the desire for a 

 balanced drawing presents itself also in diagrams of flower 

 structure. Here, however, there is no single structural type 

 concerned. The diagrams are not usually identified with any 

 specific flower, and the picturing of opposite petals, with sub- 

 tending sepals and associated stamens, a combination scarcely 

 obtainable in nature, is justified as a generalized diagram. 



An actual cross section of an apple shows clearly why the 

 representation of opposite locules in a lengthwise section is 

 inaccurate. The five locules stand out in a clear-cut star 

 pattern, which varies according to the stage of ripening, and 

 among different varieties. (Plate 3, figs. 8-12) 



Can you cut a lengthwise section so as to get an exact bi- 

 section of the pentagonal figure? This constituted an annoying 

 problem for me until I found that the five sepal lobes furnish a 

 definite clue, and that by cutting between two lobes and 

 through the opposite one, an accurate bisection of the locular 

 figure may usually be obtained. (Plate 3, figs. 5 and 6) 



What variety is best for class study? The problem of bi- 

 secting the star was further simplified when some study was 

 made of the common varieties of apples usually available in the 

 markets. Some types are definitely better than others. The 

 difference is not so much between named varieties themselves, 

 as between the long or western and the short or eastern shapes 



