November 9, 1917] 



SCIENCE 



467 



considerably exceeds both in length and in 

 thickness any of the older chromosomes. The 

 chromosome group of the male gametophyte 

 contains no element similarly distinguished 

 by its size; on the other hand, the male pos- 

 sesses a very small chromosome which seems 

 not to correspond in size to any element in 

 the female. 



The other chromosomes in the cells of either 

 sex have the form of slender rods; there are 

 noticeable differences in length between those 

 of each group. The bending and not infre- 

 quent overlapping of the ends of the chromo- 

 somes place difficulties in the way of an exact 

 determination of their number; but, subject 

 to modification by further study, it may be 

 said with reasonable assurance that the chromo- 

 some number for each sex is eight. As to 

 seven of the eight, the chromosomes of the 

 male seem to resemble those of the female; 

 but the eighth chromosome of the female is 

 probably corresponding to it in the male is the 

 the large one already referred to, and the one 

 very small chromosome. 



Of the two spindles formed in each spore 

 mother cell at the time of the hommotypic 

 division, one shows a large body which is some- 

 times plainly two-parted; no element appears 

 on the other spindle that approximates in size 

 this large chromosome. It has been reported 

 that in at least one species of Sphwrocarpos 

 two of the spores of each tetrad develop into 

 male plants and the other two into females. 

 Observations which I have made, although 

 as yet in limited number, indicate that the 

 same rule holds for S. Donnellii. The cyto- 

 logical results here reported seem to show that 

 in consequence of the chromosome distribu- 

 tion in the reduction divisions two of the four 

 spores derived from a single mother cell re- 

 ceive each a large chromosome (and seven of 

 smaller size), and these spores develop into 

 female plants ; and that each of the other two 

 spores receives a small chromosome instead of 

 the large one, and, on germination, gives rise 

 to a male plant. 



The resemblance between this history and 

 that of the chromosomes of certain insects, 

 such as Lygaus and Euschistus, which pos- 



sess a large X- and a small Y-chromosome, is 

 obvious. It is too early to conclude that the 

 particular chromosomes with respect to which 

 the male and female gametophytes of Sphcero- 

 carpos differ are the bearers of definite sex- 

 determining factors; but it seems not unlikely 

 at least that the greater size and vigor of 

 growth of the female gametophyte are associ- 

 ated with the greater amount of chromatin 

 that its cells contain. 



Charles E. Allen 

 XJnitersitt or Wisconsin 



THE AMERICAN ASTRONOMICAL 

 SOCIETY 



The twenty-first meeting of the society was held 

 August 29 to 31 at the Dudley Observatory, Al- 

 bany, N. T., about ninety members and visitors 

 being present. The arrangements for the meeting 

 were admirably carried out by the host. Professor 

 Benjamin Boss, acting also for the trustees of the 

 Dudley Observatory and the department of meri- 

 dian astrometry of the Carnegie Institution of 

 Washington. The activities included an excursion 

 to Saratoga Lake and a visit, at the close of the 

 meeting, to Vassar College and its observatory. 



Various committee reports and items of business 

 were considered by the society, among others the 

 question of the daylight saving movement, and 

 when an informal expression of opinion was called 

 for, the vote stood 



In favor of daylight saving 18 



Opposed to the plan 22 



Neutral 6 



46 



Another matter in the same connection, which 

 would affect only astronomers, was a proposal com- 

 ing from England that the astronomical day be- 

 gin at midnight instead of at noon as at present. 

 A test vote showed that a large majority of the 

 members present were opposed to the change, but 

 after some parliamentary procedure it was agreed 

 to refer the matter to a committee to make a re- 

 port back to the society. 



Officers were elected for the ensuing year as fol- 

 lows: 



President — Edward C. Pickering. 



First Vice-president — Frank Schlesinger. 



Second Vice-president — W. W. Campbell. 



Secretary — Philip Pox. 



Treasurer — ^Annie J. Cannon. 



