INTRODUCTION 



The material of this "Experimental Embryology" represents many years of the most 

 intense research on the part of innumerable embryologists, from all parts of the world. 

 The author disclaims any originality except in those sections relating specifically to his 

 particular investigations. The book is a compendium of data, directions, and references 

 not generally found in textbooks, but information which is necessary in training the pro- 

 spective experimental embryologist in the fundamentals of this relatively new and dynamic 

 field of research. 



There are contained herein some 50 separate experimental procedures, from Andro- 

 genesis to Xenoplastic Grafts, all of which have been tested in the course "Mechanics of 

 Development" developed by the author while at New York University. The present, com- 

 pletely rewritten book incorporates all the improvements in the various techniques that 

 have come to the author's attention. Each procedure is presented as foundational to 

 some basic concept so that the qualified graduate student may be stimulated to pursue 

 further research in the field. The approach is entirely experimental ; the subject matter 

 is exclusively the embryo. 



The organization of each exercise is based upon the general plan of a publishable scien- 

 tific manuscript. The usual historical background is omitted, and the discussion (if any) 

 is limited because this is the function of related textbooks. The reference list contains 

 only the most recent and pertinent papers, and certain review articles. Only Occasionally 

 there are included papers more than 15 years old, and these because they have been es- 

 tablished as classics within the field. It is felt that interested investigators can acquire 

 a complete bibliography through the references given. 



It is Recommended that the Student's Report Include the Following: 



1. EXPERIMENTAL PROCEDURE: Any modifications of the procedure as outlined. 



2. EXPERIMENTAL DATA: This section must be complete in every detail. 



3. DISCUSSION: This should be based upon "2" above. 



4. CONCLUSIONS: These should be based entirely upon the findings of the student. 



5. REFERENCES: Only new references which are not included in this exercise. 



It would be impossible for any student, under any conditions, to complete the work out- 

 lined in this book during a single academic year. There are three solutions to this matter, 

 all of which have been tried in our laboratory and any of which is satisfactory: 



1. Assign a new procedure for each of the regular weekly laboratory sessions. This is 

 a very heavy assignment and the student would necessarily spend more than the usual 

 four hours per week in the laboratory. The plan has the advantage of making it sim- 

 pler for the instructor to anticipate the needs of the entire class, from week to week. 

 He can often schedule the procedures in such a way that they follow in a natural se- 

 quence and often conveniently overlap. The major disadvantage is that the student 

 acquires only a passing acquaintance with the various techniques and is apt to assume 

 that he is master of all of them. 



2. Select a logical series of experimental procedures designed to be completed during 

 the first semester, and progressing from the gross to the microscopic, the crude to 

 the refined, the simple to the complex. There is no attempt to cover the entire 

 gamut of techniques. The responsibility of representative selection falls on the in- 

 structor, but the student will be quite thoroughly grounded in the basic procedures, 

 and will thereby be qualified later to pursue independent investigation. This has been 



