will be decades before we outgrow the zoological age of Linné But his great work was undoubtedly reptilian embryology—indeed his papers on the gastrulation and embryonic membranes of turtles have long become classic. Here, for example, he first gave the correct interpretation of the primitive streak, discovering the rudiment of the yolk plug and enabled comparisons, on the one hand, with the amphibian, on the other, with avian and mammalian types. Here, also, he gave the first satisfactory explanation of the relation of the archenteric to the subgerminal cavity, and the peculiar growth of the sero-amniotic canal, which, by the way, one of his pupils afterwards demonstrated in the chick. It is in a manner the test of the bigness of Mitsukuri that with the keen interest in his purely morphological work he did not fear loss of dignity by contributing to economic subjects. A delightful little paper is his report on Japanese oyster culture, quite after the fashion of his old teacher, Professor Brooks.
THE SPRUCE TREE HOUSE OF THE MESA VERDE NATIONAL PARK
Dr. J. W. Fewkes has performed a useful service in exploring and restoring one of the great aboriginal monuments of the country, and the Bureau of Ethnology has now printed a description of the ruin. The Spruce Tree House and the Cliff Palace, the largest of the ruins of the Mesa Verde Park, were discovered by native cattle herders, and were first adequately described by Baron Gustav Nordenskiold in 1893. The imposing ruin shown in the illustrations extends 216 feet under the over-hanging cliff. It contains about 120 rooms and probably housed some 350 people.
The buildings are divided by an alley into two sections, the northern being the larger and the older. There are in all eight subterranean rooms, which were used for ceremonial purposes and are known as kivas. Above these are plazas used for dancing and other ceremonies, and about the plazas are the living and other rooms, sometimes
