Mabch 19, 1909] 



SCIENCE 



465 



into tie dark liquid and then bounce out 

 again. To find out what really happens we 

 have only to inspect the photographs of the 

 drop as it enters the liquid. It forms a hol- 

 low bowl or crater six or eight times its own 

 size (in diameter), the milk flowing up the 

 steep sides in radial streams; surface tension 

 then pulls down the walls of the crater, the 

 milk streaming back from all sides towards 

 the center of the crater from which a foun- 

 tain rises, carrying the reconstructed milk 

 ■drop upon its summit. 



Even more interesting is the study of the 

 •difference in the nature of the splash in the 

 <iase of a highly polished marble and one 

 which has had its surface roughened with 

 «and paper. In the former case we have 

 what Worthington has named the "sheath" 

 splash, which is characterized by a very 

 curious flowing up of the liquid around the 

 surface of the sphere as it enters the water, 

 the marble entering the liquid with little or 

 no sound and the production of no bubbles. 

 If the surface is roughened the liquid does 

 not glide up the surface but shoots off tan- 

 gentially to the sides, forming the " basket " 

 splash, which is distinctly audible, and is fol- 

 lowed by a violent bubbling of the liquid. 

 The author advises every one to have a bag 

 of marbles hung up in the bath-room, and re- 

 peat these experiments in the bath-tub. In 

 addition to the wonderfully interesting photo- 

 graphs there is much valuable and entertain- 

 ing descriptive matter, and the theory of the 

 phenomenon of the splash is very fully dis- 

 cussed in its relation to surface tension, 

 gravity, viscosity of the fluid, etc. 



As the author points out a kinetoscope 

 capable of securing a continuous series of 

 pictures showing all of the various phases of 

 a single splash is much to be desired. Such 

 an instrument ought not to be difficult to con- 

 struct. It would not be necessary to have 

 the film brought to rest for each exposure, as 

 is the case in the ordinary instrument, pro- 

 vided the illumination was effected by prop- 

 erly timed electric sparks. The most inter- 

 esting stages of the phenomena are over in 

 about two tenths of a second, and it would be 

 necessary to secure about one hundred photo- 



graphs during this space of time. When run 

 through the machine at the rate of seven per 

 second we should have a quarter of a minute 

 to study the phenomenon. The sparks could 

 be timed by putting a make and break in the 

 primary circuit of an induction coil, so ar- 

 ranged as to be operated by the mechanism 

 which carried the film along. 



E. "W. Wood 



SPECIAL ARTICLES 



A NOTE CONCERNING INHERITANCE IN SWEET 



CORN 



In the polymorphic species, Zea mays L., 

 the sweet corns, called Zea saccharata by 

 Sturtevant, have been considered as a single 

 subspecies group characterized by a hard, 

 translucent and more or less shriveled condi- 

 tion of the endosperm. Correns' has shown 

 that this character is due simply to an ina- 

 bility to complete the formation of normal 

 maize starch, and further, that the presence 

 and absence of this starch-forming ability act 

 as an independent character pair in inheri- 

 tance. No other feature is peculiar to the 

 group: varieties characterized by black 

 aleurone cells, red pericarp, yellow endosperm 

 and the other salient points common to dent 

 and to flint corns, are all found in the sweet 

 corns. Their claim as a subspecies group 

 thus rests entirely on the first-mentioned char- 

 acter. 



The ■ following evidence, however, indicates 

 that sweet com varieties do not belong to a 

 unit group, but consist both of dent corns 

 and of flint corns which have lost their orig- 

 inal starch-forming power. This condition 

 may have come about through mutation in 

 each of these groups, but from what we know 

 of the early history of the sweet corns, it is 

 more likely that the change took place among 

 the flint types and was extended by hybridiza- 

 tion. 



The dent corns are distinguished by a corn- 

 eous starchy part of the endosperm which 

 lies at the sides of the kernel and surrounds 



^ Correns, C, " Bastarde zwischen Maisrassen 

 mit besonderer Beriicksiclitigung der Xenien," 

 Bibliotheea Botanica, 1901. 



