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		Discussion and Conclusion This experiment showed that it is possible to transplant the eye-forming region of the Axolotl embryo without killing the host (Figure 18). Furthermore, the grafted eye precursors continued to develop into eye-type cells. This illustrates that the cells of a late-stage Axolotl embryo seem to have undergone determination and are now of particular cell lineage, reducing their potentiality. It is therefore plausible that events of specification and determination in the eye-forming region take place during gastrulation. In practice, the attrition rate of embryos was very high. Over the period of the experiment, only about 69% of the procedures that were attempted were successful. Five days post-operatively, only one embryo survived with its graft intact. This was probably due to our inexperience. Hence, any attempts to reproduce this experiment should allow for a high attrition rate. This experiment could also be improved somewhat. In order to collect more uniform data, it would be helpful to carry out post-operative observations at standard times in the day; however, class schedules prevented that for this experiment. With a greater number of people carrying out observations, taking observations at standard times would have been possible. In addition, any dead material should be removed from the dishes immediately and the water changed, or if possible, all hosts should be places in separate containers in order to prevent contamination. It is thought that dead and dying embryos may contaminate other, healthy embryos present in the same dish (Cebra-Thomas, personal communication). Again, due to class schedules, some embryos were left in the same water as dead or dying embryos, which may have induced their subsequent death. This would explain why several embryos tended to die at the same time. For a first attempt, this experiment was quite successful. The results and data collected were illustrative of late-gastrulation differentiation in Axolotl embryos, and provided worthwhile technical experience for the students involved. References Cebra-Thomas, J. 2004. Developmental Biology Lab Compact Disc * Contains procedure for making eyebrow knives and tungsten needles *(Photographs 1-3 courtesy of J. Cebra-Thomas, 4-19 taken using equipment from the laboratory of Dr. Cebra-Thomas) Cebra-Thomas, J. 2004. Developmental Biology Lab Staging Series Portfolio (personal collection) Gilbert, S.F. 2003. Developmental Biology, 7th ed. Sunderland, MA: Sinauer Associates; pp: 305 -395. Gilbert, S.F. 2003.Developmental Biology website Hamburger, V. 1973. A Manual of Experimental Embryology, The University of Chicago Press, Chicago, Ill