(Witness: Merriam.)

Doctor MERRIAM. When the Biological Survey undertook this work the laws of temperature control of the geographic distribution of animals and plants were unknown. We asked the Weather Bureau for certain temperature data, which they kindly furnished. This enabled us to study the problem, and we finally succeeded in working it out.

The CHAIRMAN. But the Weather Bureau has practically all that data, has it not?

Doctor MERRIAM. It had the data necessary for solving the problem, but had not worked out the problem. That problem was worked out by the Biological Survey through the cooperation of the Weather Bureau.

The CHAIRMAN. What do you rely on when you work up your isothermal zones? Do you rely on the actual results from the Weather Bureau, or the more or less indefinite and uncertain results of the migration of certain animals whose habits you have described?

Doctor MERRIAM. The isothermal maps are based on temperature data. The life-zone maps are not based on the movements of migratory animals, but on the presence of animals and plants that do not migrate but stay in the same place all the year. Previous to our work the temperature data had never been assembled in such manner as to bring out the coincidences of temperature distribution with the actual zone distribution of animals and plants. We wanted to know whether the temperature at one point in each zone was the same as in another part; we wanted to find what these temperatures were and how they could be expressed in figures, and we have finally succeeded in working that out.

The CHAIRMAN. What did you use as your basis for working those temperatures out?

Doctor MERRIAM. We used the ordinary temperature records, and in platting them made a great many tentative experiments, taking temperatures for different periods of the year and computing them and placing them on maps.

The CHAIRMAN. Were those temperatures taken with instruments? Doctor MERRIAM. Yes; they were the regular recorded temperatures; but we were in the dark as to what set of temperatures

The CHAIRMAN. Where did you get those records; from the Weather Bureau?

Doctor MERRIAM. Yes; we asked the Weather Bureau for the temperature data. I had worked on the same problem in New York State years ago, before I came here, and had computed thousands of temperatures there, and had platted them on maps, but I did not succeed in working out the problem until some years after I came here. The CHAIRMAN. After having worked it out what use is made of that result?

Doctor MERRIAM. The use is to enable us to state what temperature units are required by the different native species and the different cultivated crops. This may be expressed in temperature units, and may be shown on maps. In many cases a valuable crop will be a commercial success in an area comprising parts of two adjoining life zones where certain conditions of temperature and humidity prevail. We are trying to mark out all such areas for the benefit of the practical farmer who wants to know when he goes into a new country

(Witness: Merriam.)

what he can grow on his farm without the necessity of expending thousands of dollars in experimenting with crops which may or may not grow there at all.

The CHAIRMAN. You make practical experiments, do you, for the purpose of ascertaining under what conditions plant life will develop and come to maturity? Is that it?

Doctor MERRIAM. No. We find out by a study of the native fauna and flora what and where the natural areas and their subdivisions are, and show these on maps. Then we ascertain what crops grow in the several areas as a commercial success. We do not care what crops grow in hothouses or under peculiar conditions, but endeavor to ascertain what crops are of real value to the farmer in each area. We publish a list of these crops in connection with maps showing the location and extent of the areas.

The CHAIRMAN. But what is the Plant Industry Bureau doing all this while in that same territory?

Doctor MERRIAM. The Bureau of Plant Industry is doing no work of this kind, so far as I am aware, except that, in introducing plants from one country to another and recommending the introduction of plants from one part of the United States to another, it has the advantage of our maps. It has the advantage of our work as far as

The CHAIRMAN. Are they not making practical experiments in the growth of plants in various sections?

Doctor MERRIAM. Certainly.

The CHAIRMAN. For the purpose of ascertaining whether the climatic conditions are favorable and whether the soil is desirable? Are they not doing that all the time?

Doctor MERRIAM. I am not familiar with the details of their work, but it is along lines entirely different from ours. We do not overlap, but one bureau furnishes the other important information-the work of one supplements that of the other. The Bureau of Plant Industry does none of the work we are doing in mapping the life areas; that is the work of the Biological Survey.

The CHAIRMAN. Who began the work? Does your bureau precede? Doctor MERRIAM. It not only began it, but is the only bureau doing this kind of work.

The CHAIRMAN. It precedes all of them?

Doctor MERRIAM. Yes.

The CHAIRMAN. Yours is the fundamental proposition?

Doctor MERRIAM. Certainly. The Biological Survey establishes the broad transcontinental belts and the minor areas within those belts that are climatically adapted for different kinds of crops; but it does not go into matters of detail, such as local soil conditions, nor does it have anything whatever to do with experimental work with plants. That comes under the Bureau of Plant Industry. We do nothing at all of that kind.

The CHAIRMAN. Suppose, for instance, you get the results of the thermometer from the Weather Bureau in a certain locality, which would indicate, of course, a certain temperature, and you did not find present there the wild animals that according to your investigations should be in that temperature, what data governs the absence of the wild animals or the presence of the actual temperature?

Doctor MERRIAM. We have never had any such case.

(Witness: Merriam.)

The CHAIRMAN. They have always been coterminous ?

Doctor MERRIAM. Yes; we map the distribution of animals and plants as they actually occur in nature, and find that the resulting belts and areas possess definite temperature conditions, as already described.

The CHAIRMAN. That is what is called geographic distribution?

Doctor MERRIAM. Yes; this is called geographic distribution. From the study of our native fauna and flora we have been able to discover the laws governing the distribution of animals and plants, and have been able to lay down on maps certain zones and areas which prove to be adapted to certain agricultural products.

The CHAIRMAN. Has there been any movement of population resultant upon the publication of any of your investigations?

Doctor MERRIAM. I do not know of any. I do not see how this could produce any large movement of population.

The CHAIRMAN. How does the agricultural community get the benefit of this work that you are doing?

Doctor MERRIAM. It gets the benefit of it from the study of our maps and publications. Our maps have been generally adopted. Our life zones, as we have laid them down, have been accepted by the technical zoologists and botanists, where before there was no accord among them. They have accepted our work; the agricultural experiment stations have accepted it; the physical geographers have accepted it and have put our maps in their text-books, and the results of our work are taught in the schools. In other words, there is now accord as to the principal life areas of the country and their principal subdivisions. Some of the subdivisions yet remain to be worked out.

The CHAIRMAN. If the results of your investigation do not induce migration, and do not lead to the occupation of this territory, what particular advantage does agriculture, per se, get from it? I can understand how these educational benefits may flow from it.

Doctor MERRIAM. The territory is occupied now, Mr. Chairman, except the arid lands, parts of which are now coming under cultivation. We try to help the farmer by letting him know what crops are likely to be a commercial success in his area. As a matter of fact we have been asked by the Reclamation Service as to the availability for agriculture of a large area in the Carson and Humboldt Sink country in Nevada, which has been recently reclaimed by putting through the Truckee Canal, taking the Truckee River out of its course near Wadsworth and sending it down into the Carson Sink country.

The CHAIRMAN. They asked you what?

Doctor MERRIAM. They wanted to see the results of our work in Nevada, to get our zone map and our lists of crops suited to that area, so that people going in there would have the benefit of this work. The same is true of the reclamation work in Arizona. We of course cordially cooperated with them in giving them this information, and we are also endeavoring to help them in the destruction of injurious rodents.

The CHAIRMAN. Yes; that is another branch of work. Is not the development of the character of plants that can be profitably grown in a certain territory a matter peculiarly for the Bureau of Plant Industry?

(Witness: Merriam.)

Doctor MERRIAM. Not if I understand the question. In a general way our maps give that information. Our work saves the necessity of making thousands of experiments all over the country to find out what crops will grow in a particular place. When the Agricultural Department was distributing seeds in the years when I first came here, it had absolutely no guide to the distribution of the vast quantity of seeds that it was sending out every year. It would send seeds of certain varieties to places where such seeds could not possibly be of any commercial value. That was done, and the Department felt the embarrassment of it. Our maps enable the Department to distribute seeds to the right regions-to the regions where each particular variety is likely to succeed and be of some commercial value.

The CHAIRMAN. But to those of us who do not believe in the distribution of seeds that does not appeal with great force. What do you call these maps that you make?

Doctor MERRIAM. We call them zone maps. The general maps are zone maps of the United States. We are also engaged in the preparation of larger scale zone maps of the several States and have already published the one on Texas.

The CHAIRMAN. Are these zone maps the only sources of information the Department of Agriculture has on that point?

Doctor MERRIAM. Yes; the zone maps and the tables of crop adaptations that go with them. We distribute a colored zone map of the United States in the bulletin containing the lists of crops adapted to each area so far as yet worked out. Our detailed maps of distribution are very helpful in combating the destructive ravages of injurious animals, like the ground squirrels and prairie dogs and wolves and coyotes and various other noxious kinds.

The CHAIRMAN. Why is that-because they locate them?

Doctor MERRIAM. Yes. The Bureau of Entomology found out some years ago that our maps showed in advance where an injurious insect that was spreading on a particular crop would go, so that they could forewarn the people in that belt against its approaching inroads. That is because an insect, in spreading from one place to another, will follow the life zone that it belongs to and will go nowhere else. When one of the scale insects was coming east, the entomologists found our maps of much service, and entomologists have republished our maps in their own reports to show where certain insects go. Similarly, it was found that yellow fever is limited by a zone published on one of our maps eighteen years ago. The CHAIRMAN. Is that a climatic proposition or a question of an insect?

Doctor MERRIAM. It is a climatic proposition that governs the distribution of the mosquitoes responsible for the disease of yellow fever. So with various malarial fevers, and so with diseases of cattle. The CHAIRMAN. How long ago was it that you published that map which contained the yellow-fever zone, discovered by ascertaining the zone over which the mosquito flourished?

Doctor MERRIAM. Eighteen years ago. We did not know then that it was a yellow-fever zone or a mosquito zone. We mapped it from the distribution of mammals and birds and trees. The entomologists and the medical men have found out recently that the

(Witness: Merriam.)

disease is confined to the belt in question. They have found that the disease is restricted to this belt.

The CHAIRMAN. That was a coincidence?

Doctor MERRIAM. It was one of a number of facts that are coming to light every day to show that this work is accurate and that it means a great deal for mankind. If you can tell beforehand where an outbreak of yellow fever is going, you may save the country millions of dollars and hundreds of lives, just as the work we have recently done on wolves may save the stockmen of the West two million dollars' worth of stock this year.

The CHAIRMAN. With reference to the yellow-fever zone, was not that zone delimited by a careful inspection of the area over which this mosquito that transmits the fever traveled and lived?

Doctor MERRIAM. That had not been done. Recently, in getting data bearing on the problem, it has been found that all the spots where there have been outbreaks of the disease, and where this mosquito lives, are in a certain definite life zone.

The CHAIRMAN. Yes; but how did your investigations throw any light on that proposition?

Doctor MERRIAM. They established the existence of the belts which control the distribution of life. This is being recognized more and more every year.

The CHAIRMAN. And it turned out that that happened to be the yellow-fever belt?

Doctor MERRIAM. Yes; the belt of yellow fever and of various other things.

The CHAIRMAN. Have you developed any other belts than that one?

Doctor MERRIAM. Yes; we have developed belts throughout the country.

The CHAIRMAN. I mean that involved the yellow-fever proposition?

Doctor MERRIAM. No; there is only one in which yellow fever

occurs.

The CHAIRMAN. That is down around the Gulf?

Doctor MERRIAM. Yes; and it extends up the Mississippi to about St. Louis and up the coast to the mouth of the Chesapeake.

Here is a map showing the distribution of the ground squirrels, which are extremely destructive to crops in the West. In eastern Oregon and Washington two species of ground squirrels are said by those who live in that part of the country to cause a damage of several million dollars a year. In Whitcomb County, State of Washington, they put the annual damage at half a million dollars. We have undertaken the destruction of those two species of ground squirrels and have had men working there for two years experimenting with trapping and poisoning and fumigating and various ways of getting rid of them. We have finally undertaken the study of bacillic diseases and have obtained cultures of a disease that destroys one of the two species. By means of this disease in the limited area of eastern Washington, Oregon, and northern Idaho we hope to save the farmers a million dollars this year-perhaps more than a million dollars.