and the Education of Young Women." She emphasized the necessity for sex-differentiation in education, for the teaching of mothercraft, and described her own work in this connection.

Professor Roswell Hill Johnson, of the University of Pittsburgh, discussing "The Eugenic Aspect of Sexual Immorality," pointed out that sex offenders, for a variety of reasons, have a lower birth-rate than do moral people. Further, he argued that the sexually immoral as a class are eugenically inferior to the more socially-minded part of the population. It follows that sexual immorality is a eugenic agency, tending to reduce the racial contribution of an inferior class. Campaigns for sex-hygiene, then, can not be considered directly eugenic; on the contrary, they will have some dysgenic result, which should be counteracted by appropriate eugenic measures.

He

Professor Robert DeC. Ward, of Harvard University, considered "The War in Relation to Eugenics-a Problem for the United States.'' expects a large immigration of an undesirable class after the war, and described the need for some such law as that now pending in Congress, to shut out such arrivals as are biologically inferior.

Arthur H. Estabrook, of the Eugenics Record Office, told of "A Field Survey of Mental Defectives in Two Counties in Indiana." Only the feeble-minded, insane and epileptic were considered; in one county the proportion of defectives was found to be 19 per 1,000 population, and in the other 11.4.

As vice-chairman of the committee on research in plant-breeding, G. N. Collins, of the Bureau of Plant Industry, presided over the third meeting. Adolph E. Waller, of Ohio State University, explaining "Xenia and Other Influences Following Fertilization," showed that xenia, properly defined, was limited to the result of triple fusion in the endosperm of angiosperms. He suggested the name ectogony to cover the various other phenomena now wrongly included under the name of xenia-such phenomena as are represented by the common belief that the sugar content of watermelons is reduced if the flowers have been pollinated by pumpkins.

Donald F. Jones, of the Connecticut Experiment Station, reported on "The Effect of Heterozygosis upon the Time of Maturity." As one expression of hybrid vigor, he cited a cross of two varieties of tomatoes which showed a constant small difference in time of production of fruit during four years in which they were grown. Four F1 generation crosses between these varieties grown during four different years with their par

ents and compared with them had approximately the same time of production as the earlier parent. The same condition was observed in a cross between an early and a late variety of sweet corn. In a large number of crosses between inbred strains of dent maize there was a tendency to hasten the average time of flowering and maturing of the crosses as compared with their parents. The conclusion was drawn that heterozygosis may not only increase size but also permit of the production of that increased size in less time, hence greatly increasing the rapidity of growth. In respect to the time to complete growth, heterozygosis does not effect a result comparable to that produced by environmental factors, since, usually, external conditions which result in an increase in growth tend to delay maturity.

C. W. Moore, of Cornell University, described some "Studies in Semi-sterility' on Tradescantia, Alsike Clover, Alfalfa and Shirley Poppy. Results favored Compton's hypothesis that self-sterility in plants is analogous to rust-immunity in wheat. By this view it is supposed that the pollentube in a cross continues to grow in order to get adequate food supply; while in self-pollination the nutritive conditions are more favorable, the pollentube does not have to elongate much, and it therefore does not grow enough to permit fertilization.

J. B. Norton, of the Bureau of Plant Industry, described 10 years of asparagus breeding on Cape Cod, disease resistance being the primary object. Remarkable success has been secured, by hybridization and selection, in getting disease-resistant and highly productive varieties.

Professor C. E. Myers, of Pennsylvania State College, reported on "Some Preliminary Experiments in Cabbage Breeding."' All characters hitherto tested in cabbage have appeared to blend in heredity, but it is believed that this is due to the mongrel nature of the stocks. When varieties were inbred for a few generations, and then crossed, segregation was observed.

Professor H. H. Love, of Cornell University, spoke on "Some Results obtained from Certain Crosses of Avena." One probable case of linkage has been found.

Five papers were read by title only. The last session of the association was a joint one with the Botanical Society of America. The next meeting will be at Pittsburgh, December 28-30, in accordance with the plans of the American Association for the Advancement of Science.

PAUL POPENOE, Secretary pro tem.

after which it remains fixed. In CaCl, the permeability at first decreases until a certain minimum is reached: after this it begins to increase and finally reaches a constant value (as in NaCl), which signifies death.

Further experiments showed that all substances which affect permeability may be divided into two groups, (1) those which act like NaCl; (2) those which act like CaCl2. This led to the following hypothesis: Substances of the first group antagonize substances of the second group and vice versa.

Experiments were then made to test this hypothesis. It was found that substances which behave like NaCl with respect to antagonism (in experiments on growth) behave like NaCl in their effect on permeability. Substances which behave like CaCl, with respect to antagonism also behave like CaCl, in their effect on permeability. Moreover, substances like LaCl,, which antagonize NaCl more powerfully than does CaCl2, are found to affect permeability more powerfully than CaCl2. CaCl2. There is therefore a striking parallel between effects on permeability and the antagonistic effects observed in experiments in which growth and length of life are employed as criteria of antagonism.

Equally remarkable is the outcome when permeability is used as the criterion of anIt is found that all solutions tagonism. which permit normal growth are likewise solutions which preserve normal permeability.

These experiments which were originally

made on Laminaria were afterward ex

tended to other algæ, to flowering plants and to animals.

Using permeability as a criterion of antagonism, the speaker has made investigations on a great variety of substances. Time is lacking to describe these, but it may be said that the outcome in every case has

supported the hypothesis. This was strikingly shown in investigations on organic substances (non-electrolytes), a number of which were found to belong to the second group. It turned out that all of these substances were able to antagonize NaCl, as is required by the hypothesis.

This result greatly strengthened the speaker's confidence in the hypothesis which seems to serve a useful purpose by enabling us to predict what substances will antagonize each other.

As the result of these investigations we seem to be justified in concluding that there is a close connection between antagonism and permeability. Conclusions concerning such fundamental relations should be tested, whenever possible, by a variety of methods. This task was undertaken by Dr. Brooks, who confined himself chiefly to the following methods: (1) diffusion through living tissue, (2) exosmosis, (3) change of curvature of strips of tissue.2

In the first of these methods different solutions were placed on opposite sides of a piece of tissue. The diffusion of salts through the tissue was then measured.

In the second method the tissue was placed for a short time in a salt solution and the rate at which substances subsequently diffused out of the cell was measured.

In the third method strips of the peduncle of the dandelion were placed in hypertonic salt solutions and the rate of penetration of the salt into the protoplasm was calculated from the rate at which the strips recovered their normal shape after being curved by the action of the hypertonic solution (the strips remaining in the solution during recovery). This gives the same kind of information as plasmolysis but avoids the most serious errors of that method.

2 Brooks, S. C., Proc. Nat. Acad., 2: 569, 1916.

It is a very striking fact that all three of these methods agree with those already described in showing that physiologically balanced solutions preserve normal permeability, while NaCl causes a rapid increase, and CaCl, an initial decrease, followed by an increase of permeability.

This general agreement can not but increase our confidence in the conclusion that permeability and antagonism are intimately connected.

Further studies have shown that permeability serves as a delicate indicator of what we may call the vitality of the organism. By this is meant a condition of normal health and vigor and the ability to resist unfavorable influences. An organism which has normal permeability (as shown by determining its electrical conductivity) behaves normally in all respects and lives a normal length of time under laboratory conditions, while one which has abnormally high permeability behaves abnormally and does not live the normal length of time. Hence it would appear that we can treat vitality quantitatively, for if the vitality of a large number of organisms is measured in this way we obtain a variation curve: this indicates that vitality may be treated in the same manner as any other character (as, for example, length or weight).

Moreover, since increase of permeability indicates injury, we have a method of measuring injury and of distinguishing quantitatively between temporary and permanent injury. It is found that great fluctuations of permeability are possible without permanent injury. These fluctuations may control the metabolism of the cell.

These studies show that all agencies which sufficiently alter the normal permeability of the protoplasm (such as poisons, excessive light, heat, electric shock, severe plasmolysis, mechanical shock, partial dry

ing, lack of oxygen, etc.), shorten the life of the organism. This is a very striking fact and its significance seems to be unmistakable. It indicates that permeability is a delicate and accurate indicator of vitality.

An analysis of the factors which control permeability has been attempted in subsequent studies. The changes in the resistance of tissues placed in mixtures of NaCl and CaCl, have been carefully determined. These are shown in Fig. 1. A glance at the figure suggests that there are two processes, one of which causes a rise, the other a fall of resistance. It is natural to suppose that these are chemical in nature and we may assume that they are consecutive reactions by which a substance M, which determines the resistance of the protoplasm, is formed and broken down according to the formula

A → M→ B.

It may be assumed that M is a substance at the surface of the cell which offers resistance to the passage of ions.

It is evident that if the first reaction Α →M is more rapid than the second, M will be formed more rapidly than it is decomposed and will increase in amount. Eventually, as the supply of A becomes exhausted, the formation of M will go on more and more slowly, so that it will no longer keep pace with the decomposition. The amount of M will then diminish until it finally disappears or reaches a fixed minimum (this corresponds to the death of the tissue). It is evident that if the relative velocities of the two reactions A→M, and MB be properly varied the curves of resistance will rise and fall rapidly or slowly in the manner shown in Fig. 1. It can be shown that these assumptions enable us to account for all the experimental

curves.

A point of importance is that the veloci

It is evident that the agreement between observed and calculated values is remarkably satisfactory. In regard to the theoretical procedure it should be said that in constructing equations for the curves the minimum number of constants has been employed and the attempt has been made to proceed with the fewest and the most natural assumptions. These assumptions appear to be very reasonable, for it is evident that there must be two processes in order to produce a rise and fall of resistance and that their speed must be regulated by NaCl and CaCl2. It is also apparent that these salts must enter into some sort of combination with a constituent of the protoplasm and it is evident that this compound may regulate the speed of these processes.