Page:Popular Science Monthly Volume 41.djvu/624

606 truth of the theory. One of the laws of evolution is that animals, in their growth from the egg to the adult, pass through conditions which represent, more or less clearly, the different stages through which the line of descent has come. Thus, the existence of rudimentary gills, with the cartilages and blood-vessels proper to gills, in the human embryo, is taken as an indication that at one time the ancestor had gills which were functional in other words, that man has descended from a fish-like form. There are, however, great differences in the completeness with which this record of ancestral history has been preserved. Speaking generally, more features have been dropped by the fresh-water and terrestrial forms than by those of the sea. In the latter there frequently hatches from the egg a larva which bears not the slightest resemblance to the adult: the young sea-urchin shows not a feature of the spiny creature we find in the holes in the rocks; and these changes—metamorphoses they are called—are fraught with interest and instruction to the student who goes deeper than ascertaining the mere name of the form he collects. So we can see that, if the ocean offer such advantages, a laboratory for the study of Nature should be on the shore.

Not all places on the coast are equally suitable for study. At one there is nothing but sand; another has rocks and no sand or mud; a third has the water vitiated by the mouth of some river constantly pouring in fresh water, which makes the neighboring ocean brackish; a fourth is contaminated by the sewage of a large city. All these conditions conspire to make the region poor in life. The proper place for our studies must have rocky points; stretches of mud and sand exposed at low tide; currents to bring constantly the pure water of the sea; and such localities are not abundant. It was over twenty years ago that the late Professor Spencer F. Baird, of the Smithsonian Institution, recognized the advantages of Woods Holl, not only for the investigation of the problems of pure science, but for the study of the many questions of more economic importance connected with the supply of food-fishes of the country. So, year after year, he and his assistants came here and worked through the summer months. Some made studies of the fish of the region; others collected the other forms of life, for among these we must seek the food of the fishes; still others traced the life-histories of the injurious as well as of the valuable forms; while still others worked at the problems of artificial hatching and the like. As the work went on it outgrew the limited quarters afforded by the barn-like building on the lighthouse wharf, and so Congress granted the money for the present buildings, the finest for their purposes of any in the world.

These buildings were completed shortly before the death of Professor Baird. On the one side is the Dormitory and Mess Hall,