the most frequently followed program at New York Univeristy during the first semes- 

 ter. During the second semester the students have been assigned individual and or- 

 iginal problems for investigation. 



3. Assign some of the introductory procedures to the entire class, such procedures as 

 "Induction of Ovulation", "Breeding and Care of Embryos", and "Temperature and 

 Rate of Development". Then delegate each student to carry out two or three inte- 

 grated procedures, with the responsibility of completed and thorough work later to be 

 reported in full to the class. This plan deprives the student of experience in many of 

 the techniques in experimental embryology, but it places upon him a responsibility to 

 the entire class which often kindles the research attitude. By such a plan most of the 

 exercises can be attempted by an average class of about 15 students. 



A suggested sequence of exercises, which has been used at New York University, is 

 given below. The assignment is based upon a weekly class session of about 4 hours, and 

 supplemental time as may be required by the individual student. 



1. INDUCTION OF OVULATION AND ARTIFICIAL FERTILIZATION 



2. NORMAL DEVELOPMENT 



a. Relation of temperature to early development. 



b. Relation of osmotic pressure to early development. 



c. The appearance of behavior patterns. 



3. EXPERIMENTS WITH THE EGG 



a. Germinal vesicle studies. 



b. Artificial parthenogenesis. 



c. Androgenesis. 



4. EXPERIMENTS WITH THE CLEAVAGE STAGES 



a. The effect of unequal pressure on cleavage. 



b. The production of double embryos. 



c. The behavior of isolated embryonic cells. 



5. EXPERIMENTS ON THE BLASTULA AND GASTRULA 



a. Vital staining and morphogenetic movements. 



b. The organizer. 



6. EXPERIMENTS WITH THE NEURULA 



a. Parabiosis. 



b. Regeneration. 



c. Embryonic inductions in the blastema tissue. 



7. EXPERIMENTS WITH LATER STAGES 



a. Wound healing. 



b. Hypophysectomy. 



c. Limb or eye transplantations. 



This program would carry the student through about 1^ semesters. There would remain 

 about 2 months during which the instructor could direct the students in some of the more 

 difficult techniques with either the fish or the chick embryos. 



Through the very generous help of Dr. Jane Oppenheimer and Dr. Nelson T. Spratt, Jr. 

 the sections on fish and on chick embryos have been expanded very considerably. It is 

 believed that the traditional reluctance to use these forms is being broken down by the 

 brilliant work of investigators such as these, and the laboratory of experimental 



