Page:Popular Science Monthly Volume 55.djvu/481

Rh the general courses bad been decreasing, it became evident that the giving of general information had accomplished a mission, but that there was a demand for more specialized courses of study and that a change of policy was warranted. It was therefore determined to abandon the general courses and continue the special prolonged laboratory courses.

Since 1891 all lessons have been given either in the form of laboratory lessons or field work, and the school was organized and conducted upon a new and more effective basis. The teachers have been required to keep notebooks and attend examinations in order to be candidates for the certificates which have been, and will continue to be, granted to those who have completed a series of lessons.

In the fall of 1890 was begun a course of lessons on paleontology which had been planned for some time but had not been previously undertaken because the teachers lacked the knowledge of the elements of zoölogy and geology which was a necessary preparation for those taking up the study of the history of animals as found in the earth's crust. The members of this class, which now began to make systematic observations upon fossils, were found to be sufficiently prepared to study certain groups which illustrated the laws of evolution. The class was limited in number and was under the instruction of Professor Hyatt, who for five years conducted the most advanced course of lessons ever given in The Teachers' School of Science, and such as have not elsewhere been offered to teachers nor to many classes of college students.

The lessons began with general instruction in the use of the microscope, the structure of cells and their union and differentiation into tissues, and then a study of simplest organisms—Protozoa. The work was continued through Porifera, Hydrozoa, and Actinozoa, and the types of fossils compared with their living representatives. The periods of occurrence of fossilized remains in the rocks were noted, and the characteristics of the different periods mentioned, but details of stratigraphic character were subordinated to the tracing out of the relations of the animals and the laws which governed the evolution of their forms. Special attention was given to those classes whose history is most complete and which furnish the best specimens for examination.

Echinodermata, represented by a large number of both living and fossil forms, was made the subject of study the second winter. The common starfish was examined in detail, and with it were compared other members of its class—Asteroidea, living and fossil forms in Ophiuridea and Echinoidea, the modern Holoithuroidea, the ancient Blastoids and Cystoids, and both extinct and modern Crinoids, the last of which were illustrated by alcohol specimens of