918 



SCIENCE 



[N. S. Vol. XXXVII. No. 963 



need no setting forth. The search for them 

 is one of the imperatives with those who ex- 

 periment or those who cultivate plants and 

 once begun becomes fascinating — indeed ir- 

 resistible. The seeker is so seldom rewarded 

 — correlations are not common phenomena — 

 that haste may be pardoned in publishing a 

 discovery. 



This spring a most striking correlation in 

 the peach, which seems not to have been noted 

 before, came to the attention of the writer. In 

 the work of describing the flowers of a consid- 

 erable number of varieties of peaches, Mr. 

 Charles Tubergen, of the horticultural de- 

 partment of this station, found that there was 

 a somewhat remarkable difference in the color 

 of the inside of the calyx cups of different 

 varieties. In some of the blossoms the color 

 of the inner surface of the cup was green, 

 usually a light green but varying somewhat in 

 different varieties. In other varieties the 

 cellular tissue of the inner part of the cup 

 was a deep orange in color — not the surface 

 alone but the tissue to the depth of several 

 layers of cells was orange. In no other part 

 of the calyx, the blossom, or the plant, in the 

 spring of the year, does there appear to be a 

 similar color. 



Upon investigation it was found that the 

 flowers having the green cup were those of the 

 white-fleshed varieties while the blossoms 

 with the orange cup were those of the yellow- 

 fleshed ones. We were able to observe the 

 character in two trees each of 307 varieties of 

 peaches and of 47 varieties of nectarines. Of 

 the peaches 145 varieties were white in flesh 

 and green inside the calyx-cup; 162 were yel- 

 low in flesh and orange inside the calyx-cup. 

 In the nectarines white and green were corre- 

 lated in 36 and yellow and orange in 11 va- 

 rieties. 



In neither peach nor nectarine are there 

 intermediates in color of calyx-cup or in flesh 

 of fruit. The parentage of a suiEcient num- 

 ber of the varieties examined is knovsra to 

 make it certain that green calyx-cup with 

 white flesh and orange calyx-cup with yellow 

 flesh are each inherited as one in cross-breds. 



What is the explanation of this hidden con- 

 nection between colors in two organs of the 

 peach which are not only quite distinct but 

 which appear on the plant in periods as 

 widely separated as blooming-time and fruit- 

 ing-time? The correlations are so constant 

 and their hereditary behavior is such as to 

 suggest that each is a single color character 

 difi'used through the flesh of the peach fruit 

 and the inner tissue of the calyx cup. Surely 

 the two organs in which the correlation ap- 

 pears are morphologic units but the capacity 

 to produce the same color, differing probably 

 only in degree in the parts in which it is 

 found, and at widely different times, must be 

 conceived to be a physiologic unit. If so, why 

 localized in these two organs and not general- 

 ized throughout similar tissue in other parts 

 of the plant as correlated colors generally are? 



This correlation has some practical value 

 in peach-breeding, since it will often enable 

 the breeder to tell a year or two sooner than he 

 otherwise could what color of flesh his peach 

 will have since the first blossoms seldom set 

 fruit; it is of material value in classifying 

 peaches — adding another very constant taxo- 

 nomic character; through its uses for the 

 breeder and the systematist it becomes ulti- 

 mately of considerable value to peach-growers. 

 Lastly, it seems to the writer to have value in 

 throwing light on current conceptions of 

 morphologic and physiologic units in plants 

 and also presents a problem to be explained 

 as to why there is a localization of a particu- 

 lar color in two quite distinct organs. 



U. P. Hedrick 



New Yoek Agricultural 

 Experiment Station, 

 Genea'a, N. Y. 



MICHIGAN ACADEMY OF SCIENCE 

 The Michigan Academy of Science held its 



nineteenth annual meeting at Ann Arbor on April 



2, 3 and 4. 



The following is the program as given at the 



meeting. The numbers marked with a star will be 



published in the Fifteenth Annual Keport of the 



Michigan Academy of Science. 



