concurrence between the earth's solstices and equinoxes on 

 tlie one hand and earthquake frequency. 



In other words, whatever constant or measurably recur- 

 rent fluctuation may be shown to exist at those seasons 

 points toward periodicity. Since the earth's equinoxes and 

 solstices are simply phases in the inter-adjustment of the 

 earth to the sun in the course of the earth's annual revolu- 

 tion, we are warranted in investigating those prenomena, to 

 ascertain whether such readjustments may involve physical 

 action that influences to some extent seismic frequency. 



TERATOLOGY OF THE XAVEL ORANGE 

 By S. B. Parish. 



Any departure from the normal character of a plant organ 

 constitutes it a morphological monstrosity. In the navel orange 

 there are two abnormalities: first, the absence of seed, and 

 second, the presence of the so-called "navel." 



Seedlessness occurs in a number of cultivated fruits, notice- 

 ably in the banana and the pine-apple. Among the citrus fruits 

 there are seedless lemons and grape-fruit, as well as several 

 varieties of oranges. In all these seedlessness does not prevent 

 the vegetative growth of the fruit, which attains full develop- 

 ment ; but in other cases fruits having no seeds, or imperfect 

 ones, drop prematurely, or never attain full size. Such a 

 dwarfed fruit is the seedless "Zante currant" of commerce. 

 When this vine is grown along with others which bear normal 

 fruit, some berries by cross-fertilization will produce seed, and 

 such grapes will be three or four times larger than the seedless 

 "currants" on the same cluster. Unpollinated peaches either 

 fall promptly, or if they persist are small and fleshless. In thi^ 

 connection it is to be noted that the navel orange is very subject 

 to the dropping of its fruit soon after flowering, the loss from 

 this cause amounting to a considerable percentage. 



Seedlessness may be due either to inherent defect in the 

 ovular organ, or to lack of pollination. In the latter case im- 

 perfect seed will probably be present, but in the former they will 

 be wanting. The navel orange has been studied by (~)sawa, a 

 Japanese botanist, and the valuable results of his investigations 

 are presented in a recent report.^ 



Osawa finds that seedlessness in the navel orange is due 

 "chiefly to the lack or sterility of pollen grains, and partly to the 

 disintegration of the embryo-sacs." The breaking up of the 

 pollen-mother-cells begins very early, and at the time of flower- 



'Cytological and Experimental Studies in Citrus. By I. Osawa. 

 Journ. Coll. Agric. Imper. Univ. Tokyo, Vol. 4, No. 2. 



46 



