TEACHERS' SCHOOL OF SCIENCE. 463 



the general courses had 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 con- 

 tinue 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 ele- 

 ments of zoology 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 suffi- 

 ciently prepared to study certain groups which illustrated the laws 

 of evolution. The class was limited in number and was under the in- 

 struction 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 stracture of cells and their union and differentia- 

 tion into tissues, and then a study of simplest organisms Protozoa. 

 The work was continued through Porifera, Hydrozoa, and Actino- 

 zoa, and the types of fossils compared with their living representa- 

 tives. The periods of occurrence of fossilized remains in the rocks 

 were noted, and the characteristics of the different periods men- 

 tioned, 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 com- 

 pared other members of its class Asteroidea, living and fossil 

 forms in Ophiuridea and Echinoidea, the modern Holothuroidea, the 

 ancient Blastoids and Cystoids, and both extinct and modern Cri- 

 noids, the last of which were illustrated by alcohol specimens of 



