What may also be termed monstrosities are, in a way, of common enough occurrence, so much so that Hugo De Vries has established a theory of the origin of new species upon this behavior of plants. A large number, in fact, most of the varieties of roses and carnations have originated from sports. Enchantress is particularly noteworthy in this respect, as this variety has given rise to three sports that are of commercial importance, and a number of others of less value. All such sports, however, vary from the parent plant in color alone, the type of flower and the vigor and habit of the sport being usually the same as the parent. These sports that are here discussed, however, are unusual, in that they vary not only in color, but also in the type of flower and habit of the plant. They are unusual, also, because of the fact that the sporting took place when the plants were only a few months old. These are both seedlings, the result of in-breeding. It may be that the latter fact is responsible for the variation. One bore single white and pink "bull-head" flowers; the other bore single pink and deep red "bullhead" flowers. In both cases, the habit of growth was common to the type of flower borne.

PLEIOTAXY OF THE ANDROECIUM AND PETALODY OF THE STAMENS.

The variations which have been discussed are the more unusual ores. The most common form of monstrosity in carnations is that which causes an increase in the number of the petals by petalody of the stamens. Henslow characterizes this as a retrogressive metamorphosis.

The first step in this multiplication of petaloid organs is by multiplication of the stamens. In counting the number of floral organs in flowers of one of the commercial varieties, it was found that the number of stamens varied from 10 to 30. In the case of the carnation it is the anther that first assumes the petaloid form. When the increase by this method is fulfilled, there is a further multiplication by the division of the petaloidal staminal structures, and so we may find several hundred petaloid organs in the corolla. This then, would account for the large number of petal-like organs found in the so-called "bull-heads. By actual count, the writer

From these figures it can be seen to what extremes flowers can be forced. Some of these petaloid organs are very small, meaning only one-twenty-fifth of an inch across. This condition has come

about through the division of the petaloid stamens.

This condition is of great importance commercially, as one of the greatest discouragements with which the carnation grower has to contend is to get a large number of flowers with split calyces. All the bull-heads" have this fault and it is found among the commercial varieties as well, especially among those having normally a large number of petals. Several of the commercial varieties were examined, and the following averages in the number of petals were obtained:

Enchantress was available in larger quantities than the other varieties with the exception of Perfection, and as it was at this time a worse offender in the splitting of the calyx than the latter, it was chosen for study.

It was found that the number of petals varied normally between 55 and 75. Examinations were made of 150 blooms having split calyces, and the number petals in these ranged from 70 to 168, with an average of 84. In every case, the splitting of the calyx was due to the multiplication of the petaloid stamens, and in nearly every case there was found one or more adventitious buds. In one case the bloom had 116 petals and the adventitious bud formed in it had a whorl of ten stamens.

Hanslow states that such multiplication may come about under subnormal or abnormal growing conditions. While no investigations are on record which give any satisfaction concerning this important factor in the growing of carnations, it was deducted in a general way from observations of the soil experiments with carnations at the New Jersey State Experiment Station, that the proportion of flowers having split calyces is larger when an excess of water is given. Hence, the soil proportions, as affecting the waterholding capacity of the soil, is also a factor. It is probable also that low temperature and other conditions which may tend to retard the growth are contributing factors.

From the few facts here presented, it is seen that the carnation is an extremely variable plant. These variations are interesting not only from a botanical standpoint but directly affect the success and the profits of commercial florists.

Further investigation is necessary to determine how the variations previously mentioned can best be controlled from the standpoint of practical greenhouse management.

PROFESSOR GOURLEY: I would like to ask to what extent the carnation inherits colors.

PROFESSOR CONNORS: Our knowledge of color inheritance in the carnation is about as extensive as with other flowers; little is known. This is especially true in the carnation, since we know practically nothing about the parents. Hence it is now hit or

miss. We find reds giving yellows, whites, pinks, and variegated. We find reds, the petals of which are colored almost as soon as formed and others that are not red until exposed to the light. PROFESSOR GOURLEY: And whites?

PROFESSOR CONNORS: We crossed whites and yellows and had red appearing there. Whether the red is from the yellow or the white we do not know, although yellow seems to be a component of the red color and in yellow carnations there seems to be a recessive red. There are no recorded investigations in breeding carnations for color inheritance and our own experiments have not proceeded far enough, as yet, to publish any definite conclusions.

PRESIDENT HEDRICK: Professor C. L. Fitch has two papers; the first one is "Some Ecological Notes on the Potato Plant as Evidence of its Original Habitat;" the other is "Observations on a Bastard Type of the Pearl Potato."

SOME ECOLOGICAL EVIDENCE OF THE ORIGINAL HABITAT OF THE IRISH POTATO, SOLANUM TUBEROSUM.

BY C. L. FITCH, Iowa State College, Ames, Iowa.

There is at this time a great deal of interest in the breeding and introduction of new varieties of potatoes and in tracing our common commercial sorts back to their original sources.

Some recent physiological and ecological studies by the writer are offered as suggestive of the type of structure desirable (if such structures are in existence) in a potato adapted to the corn belt, a territory which has a comparatively warm dry air and a relatively close grained subsoil. These studies also afford significant evidence of the conditions under which in South America we might expect to find in their original habitat, the wild Solanums that produced our cultivated sorts.

The structure of the stoma of the potato leaf would seem to indicate that the plant came from a region of moist atmosphere in that there is no special means of protection against the loss of moisture during respiration, but rather the readiest access afforded the outer air to reach the moist cell walls within the leaf. The stoma is of a form to facilitate the escape of moisture rather than to protect against the loss of water. The stoma projects like a low crater and is unguarded by the devises often found on other plants. The stoma, for instance, of the alfalfa, which we know to be native to an arid climate, is sunken and provided with a shielding ring or awning above the guard cells. In connection with the evidence of the stoma, we may note also that the chief fungous enemies of potato leaves, early and late blight, both flourish in a damp atmosphere.

The structure of the root cap is likewise significant. The cells seem to have no coherence and are readily broken from one another by agitation in water or by slight abrasion. Whether taken from a sprouting seed, from a root in the field, or from a pot in the greenhouse, I have found the cap hardly able to hang together and

readily broken up by dragging on soft, wet filter paper. This is such a root cap as might be produced by growing for untold ages in soils so loose and open that the plant root had little or no need for a protecting cap. The conclusions from the physiological needs of the potato roots for cool and open soil, as expressed quantitatively in experiments reported by the writer to this society last year, and the conclusions from the structure of the root cap, are the same. In studies of potato root systems in widely different soils and in several varieties, I have found that extreme crookedness of growth is characteristic, and that in a half dozen potato districts of Colorado, potato roots do not penetrate raw clay, though they may go down a rotten sage brush root and send out branch roots into the sandy streaks between the layers of clay.

In rather heavy loams, potato roots do not go down alfalfa roots when the sod was broken in the spring, but when the alfalfa had been broken the year before and the alfalfa roots had commenced to decay and to pack their holes less tightly I found potato roots following alfalfa roots down through clay for as much as four feet. On much of the successful potato soil of the Carbondale district potato roots do not penetrate, unless preceded by alfalfa, for more than two feet, and in my judgment, potato growing on such soils would be impossible except for the excellent drainage secured by the steep slope of the mountain mesas.

If we compare the potato root habit and root cap with the root habit and root cap of the alfalfa, we find a striking contrast. The alfalfa root goes straight down through raw clay soils unpenetrated before by any root, and the alfalfa root cap is snug and loses very few cells when subjected to rubbing, but seems rather to cover the root like a glove finger.

Physiologists and ecologists regard these needs and structures of potato roots as evidence of the conditions under which the plant has grown for ages past. We may apply these facts to the examination of the claims that certain localities in South America are the original habitat of our varieties of potatoes.

It is commonly accepted that the potato is native to South America and the question has arisen as to whether its native habitat is to be found in the maritime districts or in some of the more arid Andean regions. The physiological and ecological data outlined above are submitted as one source of evidence in answer to this question. To the writer they clearly suggest its being a plant native to sandy open soils and maritime atmosphere, or misty well drained mountain slopes free from prolonged and heavy rains, if such there be.

OBSERVATIONS ON A BASTARD TYPE OF THE PEARL POTATO.

BY C. L. FITCH, Iowa State College, Ames, Iowa.

The object of this paper is to call attention to an extreme case of degeneracy and alteration of both the tuber and haulm of the Pearl potato. Except where otherwise stated the observations

The

herein noted apply to the Greeley district of Colorado. Pearl is almost the exclusive variety of the Greeley district. The same variety is known as the Peerless in Wisconsin.

The Pearl produces a small proportion of tubers of a very different shape when planted upon the rich irrigated alfalfa lands of this section, especially if the seed comes from dry farming sections. Probably the even lay of the land with the tendency to soakage and high soil temperatures are important factors causing this variation.

The normal Pearl potato is somewhat wide and recessed at the stem and has a somewhat nosed tip and a wide flattened body. The bastard type is thicker in body and has a distinctly rolled-in seed end and a different stem end. It has fewer eyes and they also are smaller, sharper and deeper. The color shows an amber tinge with the white. The bastard is without the crackled brownish epidermis which is the usual and prominent surface character of the well ripened Pearl.

The bastard type differs from the normal also in blossoming habit. The normal drops its buds and does not bloom except from late formed branches in occasional unfavorable seasons. Even when it does the flowers are pollenless.

The bastard is a better keeper than the normal type and cuts harder showing that there is a change either in composition or in structure or both.

On the other hand, the bastard form always bears large blossoms with full corollas, abundance of virile pollen in large bright orange stamens, and large fruits with an abundance of vital seeds. I have secured some fifty successful pollinations with this pollen upon the Rural and have secured an abundance of seed in the resulting fruits, indicating that the pollen is potent.

The fact that the normal Pearl tuber produces a plant that blossoms only in unfavorable seasons and then only on the late formed branches, suggests the initial stages of degeneracy due to an unfavorable environment, while the commercial fact that this great potato growing region has been unable to grow its own seed for more than one propagation from outside seed stocks, is proof in the large of degenerating conditions.

The bastard type of Pearl is well known to a thousand or more experienced potato growers of the Greeley district; many of these men have observed the conditions under which the form develops. These growers are also familiar with the type of vine on which it is borne and to which is given the same name. From long experience and careful sorting of seed and by its production experimentally, growers, seed dealers, and experimentalist agree that the bastard cannot be a chance admixture. This region grows in quantities for shipment no other variety except a small acreage of the Rural and there is no place known to the writer where seed stocks are so pure. Yet this bastard constantly appears in three colors; among the white Pearls; in the Blue Victor which is a blue strain of the same stock; and in the Peoples, which is a brown strain, otherwise than in color, also identical with the Pearl.