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yolk-mass, which I described at full length in my former paper, 

 completely checks the displacement of the oil-drops. This is to be 

 concluded already from the behaviour of the normal egg'. So in the 

 eggs of Muraena No. 4 a large number of rather large oil-drops are 

 lying at about equal distances from each other at the surface of the 

 yolk-mass. During the entire process of covering of the yolk, the 

 distance of these oil-drops remains the same, they maintain their 

 relative position absolutely, and only during the slight disfigurement 

 of the yolk-sphere, caused by the contraction of the blastodermring 

 during the circumgrowth of the yolk (fig. 4 on plate 2) the position 

 of the oil-drops is changed a little, only to become the same as 

 before, after the yolk has regained its spherical form. When these 

 oil-drops were lying loose in the yolk or in the periblast, they would 

 have crowded together at the upper pole of the egg, or at least their 

 relative position would have undergone a change (luring the covering 

 of the yolk. Only when the yolk-mass in the developing embryo 

 becomes pear-shaped and very much elongated (I.e. plate 2, fig. 6, 7), 

 the oildrops of course change their position. Even then, however, 

 they remain scattered through the yolk. 



Experiments also show the constant fixed position of the oil-drops 

 in the muraenoid eggs. When we transfix the egg-capsule carefully 

 with a tine needle, it is possible to lift one of the oil-drops or a 

 small portion of the peripheral yolk out of the egg. The other oil- 

 drops retain their normal position, and in most cases such eggs 

 develop normally and give rise to normal embryos. When we operate 

 very carefully under a low-power dissecting-microscope, it is possible 

 to leave the oil-drop connected with the periblast by means of a thin 

 protoplasmatic thread. When we do this in a very early stage of 

 development, at the beginning of the gastrulation-process, we see 

 that this oil-drop, which surely may be regarded as a fixed point on 

 the surface of the egg, retains its position in relation to the other 

 oil-drops, until it is cut off from the periblast by the growing blas- 

 todermring. In fig. 2a, 2b, 2c and 2d on plate 2 I have drawn 

 from life several stages of this process in an egg of Muraena No. 1. 

 During my stay at the Stazione Zoologica at Naples, in August and 

 September 1906, I performed several of these experiments with 

 different muraenoid eggs. They all led to the same result, and con- 

 firmed my former statements. And so I believe that my contention 

 was right and that the scheme I figured is a true representation of 

 the facts. Of course only in a general sense, for there are many 

 individual variations (so for example the case figured in fig. 3 on 

 plate 2). And after all, when we compare this scheme with that 



