348 



NATURE 



[Ma> 1 i, lyl 1 



South African grower ha« yet »uccceded in fixing the 

 number of row» In any breed to such a degree that no 

 variation occur* in that respect. 



In the course of a »eric» of breeding experiment I am 

 conducting, which are not yet completed, I have met 

 with the following interesting case. 



Thirty-three plants of " Arcadia " sugar-maize, each of 

 which bore two well-developed cars, were studied as 

 regards number of rows. On 3i plants the number on 

 the upper ear was difTrnnt from that on the lower, while 

 on 12 plants the number was the same on each ear. Of 

 the a I plants on which the numlxr of rows differed on 

 the two cars, 13 had a larger number on the lower than 

 on the upper, while 8 h:id a smaller number on the lower 

 than on the upper. The distribution of rows was as 

 follows : — 



Clait 



Upper ear Lower car 



Niimljer of 



Numberof 

 planlx in 

 each clas* 



'J 



8 

 33 



«3 



13 



33 

 The total number of ears producing any given number 

 of rows was as follows : — 



Rows ... 8 ... 10 ... 12 ... 14 

 Ears ... II ... 23 30 ... 2 Total 66 



The "Arcadia" is a white sugar-maize obtained from 

 a cross between a normally 8-rowed " Black Mexican " 

 and a white Hour-corn normally bearing a larger number 

 of rows, but 1 do not know that either was pure bred, 

 for row numbers and no subsequent selection in this line 

 had been made. 



It is generally supposed by maize-growers, in this 

 country at any rate, that the number of rows is a definite, 

 heritable character. Results obtained by crossing two 

 other breeds, an 8-row and an i8-row (each believed to 

 be pure as regards this character), have this year pro- 

 duced irregular results in the F, generation, for which I 

 have not yet been able to account. However, the case 

 described above seems to indicate that the development of 

 rows is, within certain limits, a vegetative character 

 depending in part on seasonal conditions and on food 

 supply. This view is strengthened by the fact that this is 

 the first year in which I have noticed 14-row ears in this 

 breed, all the parent ears for two or three generations 

 having been 8-, 10-, or 12-rowed (so far as I am aware). 

 At the same time, there is ample indication that, within 

 certain limits, row-numbers are inherited in the maize 

 plant, but it is doubtful whether any South African strains 

 are yet sufficiently pure-bred for this character to demon- 

 strate the point with absolute certainty. 



Joseph Burtt-D.wv. 

 {Government Botanist.) 

 Department of .Agriculture, Pretoria, April 17. 

 NO. 2167, VOL. 86] 



itrics. 

 ■ n reality. 



Absorption Marldngt Id *' K " Spectroheliograms. 



In a letter publi»h«-d in Naturk of March 30, .Mr. Hu^^ 

 ■ugge»t» that the evidence derived (rum sonic kj< 

 grams taken by M. IX-^iundres at .M»»udon roii;; 

 that which I obtained from the K-^ 



There ii> no such *' divergence 

 The dark marking bhown on our i^i.n' •. ui .m.ul 

 and described as vague and ill-defined, is douL 

 more clearly seen in the plates obtained with t! 

 high-disper!>ion spectroheliograpb, which iso 

 central abitorption line K,. 



With the dispersion available in the Kodaikinal ;:. 

 ment, the K, line is about half the width of the can. ... 

 slit, and ' iphs taken with the slit exactly c<:. . 



on K in; light of the absorption line and oi . 



side com;. uf the emission line K,. As the d-i;*. 



tlocculi or absorption markings seem to be entirely due 

 to variations in intensity in the narrow absorption line, it 

 is rather a matter for surprise that in our photograplib 

 they should be so clearly defined in many cases. In tho 

 original negatives taken on March 31, 1910, in addi:;.»n 

 to the broad, ill-defined shading already mentioned, li;:- 

 are clearly seen all the curious linear markings so bt.iui.- 

 fully shown in M. Deslandres' K, plate of this date, ;. I 

 I can find no appreciable differences in the contours of ;;: 

 markings. 



With regard to the disappearance iiormously 



e.\tended marking between March 25 and so, had Mr. I?ii>> 

 read the paragraph in my article referring to this v..::. 

 ordinary attention, he would not have suggested that ;:; 

 absence of the marking on the plate of .March 26 .. - 

 due to imperfect adiustmcnt of the spectrcAeliograph i.;;L- 

 Very possibly the disappearance shown by our plates was 

 not absolute, and K, or llo plates taken on the same day 

 would have shown the marning, but if so the reduction 

 in intensity compared with the previous day would have 

 been marked. 



The theory apparently advocated by Mr. Buss, that the 

 absorption producing these markings takes place above the 

 prominences, receives no support from our visual or photo- 

 graphic observations, and his remarkable observation of 

 a dark flat cloud hovering over the bright prominence at 

 each successive appearance east or west seems to be 

 unique ! No trace of so extraordinary a feature can be 

 seen on any of our numerous photographs of this promin- 

 ence. J. EVERSHED. 



Kodaik;inal Observatory, April 18. 



Calendar Reform. 



May I trouble you with one or two observations on the 

 excellent article which appeared in Nature of -April 27. 



Referring to the application of the principle of the <f»V« 

 MOM, or the setting aside of a day annually not int' 

 in the weekly enumeration, the author of the articl- 

 " the week can boast a most ancient lineage unintenup. u 

 by the slightest break." Is this certain? I find Dr. 

 Hale in his "Chronology," vol. i., p. 67, says: — ** If the 

 year of the Crucifixion was a.d. 31, as is most likely, it 

 follows from an eclipse of the moon in Pingre's tables, 

 .April 25, at afternoon, that the Paschal full moon that 

 year fell on March 27, which in the calculations of New- 

 ton, Ferguson and Lamy, and the computation of Bacon 

 is reckoned Tuesday," &c. I might adduce other re.Tson? 

 for doubting if the continuity of weeks has been uninter- 

 rupted. It must be remembered that for some time, at 

 any rate, throughout the Roman Empire the odd day in 

 leap year was treated as a literal — not merely as a legal — 

 dies MOM, being regarded as part and parcel of the day 

 preceding. 



Nevertheless, I agree with the author that prejudice in 

 this matter cannot be disregarded. 



But no such objections can be stated to the proposal to 

 apply this principle to the months, i.e. to treat the 365th 

 and 366th days as without the monthly enumeration, and 

 to equalise so far as possible the lengths of the months 

 so as TO give four quarters of qi days, or 13 exact weeks. 



It is hopeless to suggest that the present arrangement of 

 months has any scientific or religious sanction ^'■ 

 advantage. 



I hope shortly to present to the public more fu'l 

 arguments in fa%-our of this really nori-contenti' > ' 



