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been very unfavourable. I feel that if I had let others like this stand 

 a few more days than I did, instead of throwing them away as good 

 for nothing I should have had some more embryos produced under 

 the same conditions. During the rest of the season, I made it my 

 usual procedure to restore the cut-out piece of the shell which had 

 on removal been placed on a specially sterilized paper to its original 

 position in the shell and thus covered up the blastoderm again. In 

 some cases, the eggs were placed in the cask in this simple condition, 

 but in most cases, I pieced the cut-out piece and the rest of the shell 

 together by covering up the upper pole of the egg with common sur- 

 geons silk-plaster. — This plaster leaves much to be desired but it 

 has on the whole answered my purpose best so far. The eggs thus 

 plastered over were then placed in the casks. 



Now as to the results of these experiments. Out of 120 eggs in 

 all which I subjected to these experiments, 30 embryos have been 

 preserved after a longer or shorter period of incubation lasting from 

 1 to 15 days. Out of these 30 embryos, 12 I consider as most suc- 

 cessful and some of them present remarkable and interesting features 

 which, I believe, will repay a most careful and detailed study. In 

 some most successful ones, the embryos developed normally and re- 

 gularly almost as if they had not been subjected to any operation at 

 all. At one time success was so great that hardly any precaution 

 seemed necessary for carrying on these experiments. This statement 

 hardly accords with the small percentage of preserved embryos as 

 stated above but this fact is due to others causes. In the first place, 

 this being the first time anything of the kind was ever been attempted 

 — at least so far as I am aware — I had nothing to guide me, and 

 had to grope in dark, so to speak. In the second place, after I have 

 been at work for about 20 days when success seemed very great, such 

 a season of rain as had not been known in Japan for several years 

 past set in, and Honjö where I carried on my work being a low and 

 marshy region, the crop of mould that now sprang up was something 

 incredible and set at defiance all my precautions. After this, although 

 there were a few clear days at the very last of the breeding season, 

 I never recovered my former success. One case I very much regret 

 losing. On July 4, I opened an egg just deposited and examined the 

 blastoderm which was perfectly normal — I restored the cut-out piece 

 of the shell to its original position and plastered it over. On July 8, 

 when it was re-examined, everything was going on normally: the me- 

 dullary folds had developed and extended themselves as far back as 

 that part which I have called the yolk-plug in my Contributions to 



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