degree of manipulative skill and to these should be assigned the type of man who is naturally handy with his hands. Conversely there are problems of a mathematical nature that would be exceedingly irksome to the preceding type, whereas the theoretical type could handle them efficiently. It is the problem, then, of the research director to so arrange the work that each man of his staff will be working to the greatest advantage.

Undoubtedly the most important quality that any experimenter can have is persistence. There are many problems that require months and perhaps years of hard, discouraging work before the first ray of success can be discerned, and in such cases it requires the utmost faith in the ultimate result to enable one to keep up his interest. It is only by the careful, systematic elimination of each obstacle as it comes up and the direction of the work continually into new and more promising channels that will make successful what to the less determined experimenter would be a failure.

Perhaps it will not be out of place to say a few words about the presentation of results. In the first place, the data should be given, wherever possible, in graphical form. There are some instances where the accuracy of the results is greater than can be represented by a plot, in which case the data must be also given in tabular form, but in most cases a curve is sufficient and the tables may be omitted. When plotting curves, no points should be used except those directly computed from the experimental results, as the practice of some very reputable laboratories of taking points from a faired curve as the basis of plotting is very misleading as to the regularity of the results. On the other hand, no experimental curve should be shown without including the actual points, otherwise the results can not help but be regarded with suspicion. It is always better to present a few well checked results than a multitude of irregular ones.

One of the secrets of experimentation is to know when to stop, for it is a natural tendency to carry the work further than the value of the additional results will warrant, and it is inefficient to allow a nearly finished piece of research to drag along. There is of course, no definite point where a piece of work can be considered finished, and often times one feels that he is in a position to efficiently commence the work only when the allotted time or money is exhausted. For this reason one of the most important functions of an investigation should be the paving of the way for more extended work. Therefore every report should contain an account of the difficulties encountered, and most important the recommendations of the experimenter for the conduction of further research, for every difficulty, and every failure, should be made of value by preventing others from encountering the same obstacles.

It is urged that every investigation that produces results of interest

or value be published or in some way be made available to those who are interested. It now happens, especially in the industrial laboratories, that much work is done which is never known outside, and there is generally no reason why the results should not be published after the particular organization has received its benefit. Because of this practice a great deal of money is spent in duplicating work that has been already accomplished, and, while a certain amount of duplication is valuable as a check, it is in general very uneconomical. In the same way, it sometimes happens that similar investigations are undertaken simultaneously, and, although their results are later published, it means an unnecessary duplication. In this particular it would be of great value to have a research clearing house where all the work in preparation could be gathered together for general information.

It may be stated in conclusion that the carrying out of a piece of research will comprise in general the following procedure: First, the similar work of others is studied, especially their difficulties and failures, and from this information a plan of operation is laid out. And if there is any doubt, and there usually is, as to the practicability of the proposed methods, preliminary experiments should be conducted, from which data are obtained for use in designing apparatus and for more completely planning the subsequent procedure. In carrying out the actual work, the first consideration should be accuracy and the second, efficiency, both depending on suitable equipment and on an interested and well-organized staff. Lastly, the experimenter must organize his results, and deduce from them conclusions that will be of value in joining them with similar work and in advancing the theory and practice of the subject. Briefly, successful conduction of research depends on the foresight and vision of the experimenter in laying out the work, his accuracy, persistence and manipulative skill in carrying it out, and, lastly, his analytical ability in deducing conclusions from the results.

VOL. XII.-28.

D

A BIOLOGICAL EXAMINATION OF LAKE

GEORGE, N. Y.

By Professor JAMES G. NEEDHAM

CORNELL UNIVERSITY

URING the summer of 1920, the New York State Conservation

Commission maintained a field laboratory on Juanita Island in Lake George. The writer was placed in charge. Dr. Chancey Juday of the University of Wisconsin, was at the laboratory in August studying temperatures, plankton, and dissolved gases of the lake at different depths. Dr. Emmeline Moore, of the Commission, was detailed to assist in the work of studying the food of fishes and of tracing it back to its sources in the lake vegetation of the shores and of the plankton. State Fish Culturist, Mr. John W. Titcomb, of the Commission, was also present during August studying fishes. Messrs. Charles K. Sibley, of Kingston, N. Y., and William R. Needham, of Ithaca, were regular assistants at the laboratory during the whole of the season. Visiting naturalists who participated to some extent in the work of the laboratory at times during the summer were Mr. S. C. Bishop, New York State Zoologist, of Albany; Professor C. R. Crosby and Dr. M. D. Leonard, entomologists of Cornell University; Miss Sue J. Reid, secretary of the Chicago Nature Study Society, and Miss Jay R. Traver Supervisor of Nature Study at Wilmington, Delaware. The object of this laboratory was to determine conditions in the lake affecting the life of food and game fishes. A report has been made to the commission on fish cultural matters. And at its completion it has seemed to the writer that a number of observations made in the course of this work that are of a more general scientific sort might be helpful to other field naturalists and ought to be placed on record: hence, this paper.

The water of Lake George is "soft"; and the dominant plants and lesser animals are quite different from those of the lakes in Central New York. Doubtless the most abundant plant in the lake the one that bulks largest-is the stonewort Nitella opaca. It occurs at depths between 18 and 45 feet and covers scores if not hundreds of acres of the lake bed between these depths. It forms great meadow-like beds of erect or recumbent, soft, translucent bright green stems often three or four feet long. These beds (called "grass" by the local fishermen) furnish shelter and support for a large population of sessile algae; for case-inhabiting insects, such as caddis worms and midge

larvae; for free-living animals such as mayflies, snails and scuds, and for sessile hydras and rotifers. About these beds most still fishing is done by the initiated.

Other stoneworts observed by us were all found in quite shoal water-less than 10 feet-and the most interesting of them was the extremely delicate and remarkably pretty Nitella batrachosperma that occurred at 5 feet, on beds of yellow ripple-marked sand, and swayed in passing waves with all the aspect of a bright green frog-spittle This occurred sparingly but was found by us in places as wide apart as the head of Northwest Bay, the south shore of Juanita Island and the outlet channel below Baldwin. Two species of Chara also were found in the shoals.

In the lake bed below the level of the Nitella zone there grow two peculiar and characteristic green algae. One is a "Siphon alga” Dichotomosiphon that at 40 to 50 feet in depth is so abundant as to be a nuisance to the lake trout fishermen: the lead bob of their trolling apparatus gathers the tangled and matted threads of this plant about it and brings them to the surface in slimy dripping handfuls. This is what the fishermen know as "moss." Dr. Moore is publishing elsewhere an account of this species. The other alga, a species of Cladophora invades the depths where hardly any light penetrates. Its minute branching sprays usually about a fourth of an inch long and of very bright green color may be found sparingly, lying amid the bottom sediment at almost any depth in the lake below the shoals.

The most abundant filamentous alga of the shore is a species of Tolypothrix which fairly covers submerged stones and timbers with its little tufts of brownish-green swaying threads, always and everywhere interspersed with masses of gelatinous palmelloid forms. Among the coarser waterweeds hornwort and elodea are quite scarce and the fine tall-growing Potamogeton praelongus is conspicuous, forming some of the most beautiful weed beds of the lake. These weed beds occur mainly at depths of 10 to 15 feet. They shelter forms similar to those of the Nitella beds and many additional, including two interesting waterfleas, Acantholeberis curvirostris and Eurycercus lamellatus. The latter is abundant enough and large enough to form an important item in the diet of some of the adult game fishes of the lake.

In the plankton of the lake, diatoms of four genera were probably the most important food gatherers. Asterionella, Cylotella, Tabellaria and Fragillaria. Other algae less constant but occasionally abundant were Anabaena, Aphanizomenon, Aphanocapsa, Botryococcus, and Staurastrum. Among the cladocerans, which all season through were far more abundant than copepods, Bosmina was rather common throughout the season, Polyphemus became abundant for a time in

July, Holopedium attained an extraordinary dominance the latter part of July and two species of Daphnia replaced it in late August. On July 14th a net of No. 6 silk drawn for a few minutes in the lake gathered a solid pailful of Holopedium in a nearly pure culture. A few Leptodoras and a few Daphnias were present besides.

We found some good collecting grounds for aquatic plants and animals; and it may benefit some future naturalist who is visiting Lake George for the first time if I mention a few of them. First of all, Juanita Island itself, our headquarters, has most interesting shores. On the west the rocks rise vertically out of the water; on the north they run down in gently sloping serried low ridges of solid rock, smooth and bare as far as the breaker line; on the northeast is a broad smooth sandy beach in a sheltered bay (here was our bathing beach); on the south is a shore line of broken rocks and at the east this merges into a narrow beach of ripple-marked sand. Eastward of the Island is a deep current-swept channel, and northward is a more sheltered cross channel in which the "grass" and "moss" of the fishermen are found. There are scattering growths of Potamogeton, Ceratophyllum and Heterantheria below the breaker line (which occurs here at about 5 feet below the surface) and just above it grow Valisneria, Eriocaluon, and Lobelia.

There is a very interesting admixture of small plants growing in the rippled sand about the dock and at the edges of the beach within the bay. The most abundant plant present is one of the least conspicuous, Myriophyllum tenellum, a true sand-binder of the shore, whose tufted, slender interlaced stems lie buried in the sand, and whose many leafless red branches rise erect but an inch or so above the surface, and, draped with tufts of filamentous algae, are most inconspicuous. More in evidence is the little creeping Elatine americana, that formed close-growing patches the size of a silver dollar on the surface of the sand, and that is fairly covered in August with minute blossoms. Intermixed with it, and likewise persistently blossoming is the curious little cruciferous quillwort, Subularia aquatilis, which grows erect to a height of perhaps an inch above the surface of the sand. Another pygmy component of this inch-high vegetation is the slender creeping spearwort, Ranunculus flammula filiformis which here spreads by stolons about an inch long in single lines of progression over the sand. Another is an undetermined closely tufted spike-rush, whose roots bear numerous slender little brownish tubers.

There are also scattering plants of taller stature here; bushy little sprays of Nais flexilis, pinnate sprays of Potamogeton perfoliatus and P. heterophyllus, the latter having when grown two or three oblong leaves that reach the surface. There are small tufts of eelgrass, Valisneria spiralis, in the more exposed places on tufts of two species