108 



The Journal of Heredity 



at any rate limited, by the manner of 

 its orig;in, /. e., by the nature of the 

 germinal change by which it appeared. 

 Just as there are different tyj^es of 

 discontinuity in variation, so there are 



various methods of inheritance of the 

 differences which thus arise. These 

 methods of inheritance naturally de- 

 pend ujjon the basic nature of the 

 original change. 



ANNUAL MEETING OF THE ASSOCIATION 



THE annual Imsiness meeting of 

 members of the American Genet- 

 tic Association was held in the 

 Cosmos Club, Washington, 

 D. C, at five o'clock on the afternoon of 

 Thursday, January 14, 1915, as pro- 

 vided by the by-laws. 



The three retiring members of the 

 council were re-elected by the following 

 motion, carried by a unanimous vote: 

 "Resolved, that the secretary be in- 

 structed to cast the unanimous ballot 

 of this meeting for Alexander Graham 

 Bell, W. E. Castle and Bleecker Van 

 Wagenen to succeed themselves as 

 members of the council of this associa- 

 tion; and that this action is not to be 

 considered a precedent, but is con- 

 sidered fair because the three retiring 



members have served one year only, 

 and not the normal term of three years." 



The meeting a])proved the plans of 

 the council to hold the annual conven- 

 tion of the association at Berkeley, 

 California, August 2-7, in connection 

 with the meeting of the American 

 Association for the Advancement of 

 Science. 



At the annual meeting of the council, 

 held at the Cosmos Club at 5 o'clock 

 on the afternoon of Tuesday, January 

 19, in accordance with the by-laws, the 

 present ofificers of the association were 

 all re-elected, and Thomas H. Kearney 

 was elected a member of the executive 

 committee for the ensuing year, the 

 other two members being the president 

 and secretary, ex officio. 



Conditions of Mendelian Inheritance 



If wc take "Alcndelian inluTitaiicc" to sii^nify tlic moilc of inlicrilancc Mt'iidfl found to prevail 

 in his researches on seven difTerentiatinj^ characters in peas (except that perfect dominance need 

 not be present), the following are some of the complications which must be absent in order that 

 simple ^lendelian inheritance may appear. 



1. Each single factor must pass indifferently into half of the pollen-grains and half of the 

 embryo-sacs. There must be no such muUiplicalioji of factors as occurs in the origin of some 

 giant Primulas and Qinotheras. 



2. There must be no such coupling or rcjiulsion between tlie factors as has been found in sweet 

 peas, primulas, snapdragons, ])e;us, and velvet beans. 



3. There is usually some elimination of i)ollen-grains and embryo-sacs; but there must be no 

 elimination that has any relation to any of the factors in question, such as occurs in certain 

 Stizolobium hybrids, and doubtless in Oinotheras. 



4. There must be no inherited difference in the fertilizing jjower of different "good" pollen- 

 grains from the same anther. If a definite fraction of the pollen-grains fail to fertilize the ovules 

 (as Correns found in Mirabilis), then a selective partial self-sterility, or partial incompatibility 

 occurs, which may c(jmj)licate tlie results. 



5. The death of certain embryos within the ovules or young seeds (which seems to occur in 

 most plants), must not be due to any inherited weakness of these particular embryos. 



6. There must l)e no such difTerential vial)ility of the seeds as has been found in double stocks 

 by .Saunders, and in Qinnthera lamarckiana by DeVries. 



7. If a definite fraction of the young seedlings perish unnoted, tliis will make al)nonnal ratios, 

 as occurred in Baur's first experiments with the golden-leaved snapdragon. 



8 Plants which die before maturity must not do so from inherited weakness, or the final ratios 

 may not lie tyijieal. 



Mendel's law is only the alphabet of the subject of heredity. The simple law of gravitation is 

 also easy to grasp, l)ut much work of many astronomers was required to fit this law to the actual 

 motions of even one planet. I think that heredity may be found, in the end, to be nearly as 

 complicated as astronrmiy. 



loiiN l5i;i.l.iN(;, Florida Aurieiiltiiral Experimental Station. 



