196 Transactions of the 



There is to be noticed in some eggs a peculiarity of the first 

 two furrows, which consists in this, that they do not cross each 

 other at right angles, but form a double Y, the points of which do 

 not touch each other, but are joined by a straight hne (see Fig, 2). 



At the end of the first day the blastoderm of nearly all eggs 

 exhibits the first two furrows ; whether the blastoderm gets a third 

 equatorial furrow I cannot distinctly say ; I take it as very pro- 

 bable, because I have found that the blastoderm persists in the stage 

 of the first two furrows a comparatively long time. The next 

 stage I have noticed appeared thirty-six hours after fecundation, 

 and consisted in this, that the blastoderm seen from the surface 

 showed two quadrants in division, that is, six knobs (see Fig. 4). 



Until the end of the second day we find the eggs in the 

 difierent stages between this just mentioned and a stage in which 

 the blastoderm showed, when seen from the surface, four whole 

 furrows, that is, eight knobs. This was also the last stage which 

 could be regarded distinctly as a regular one. 



The blastoderm which I have looked at during the third day, 

 in the surface as well as profile view, reminds me very much of 

 what Strieker has described and illustrated, for we see that the 

 knobs of which the blastoderm consists do not exhibit any regu- 

 larity either in their position or in their size. I could not make 

 out any regularity even when the blastoderm exhibited in the 

 surface view only sixteen or twenty knobs. 



Until the end of the fom-th day, even when the blastoderm 

 appeared on its surface like a mulberry, I could distinguish very 

 easily the single knobs with a magnifying power of only 90 

 diameters, so that we can say that the segmentation is far from 

 being finished. 



However unequal the time may be in which the eggs of the 

 same set become developed, I must still consider, from what I have 

 seen in fresh preparations and sections, that the shortest period for 

 the segmentation is nine days. Of course the segmentation can be 

 accelerated, if we allow the eggs in very small numbers to develop 

 in the ordinary temperature of a room. 



The elements of the blastoderm between the fourth and the 

 tenth day, which can be examined in the fresh state only by 

 puncturing the egg and enclosing the blastodei'm with oil after 

 mounting it in the yolk itself, appear as pale finely-granulated 

 bodies ; in many of them there is a central vesicular nucleus-like 

 body to be seen. The elements exhibit distinct amoeboid move- 

 ments : from the protoplasm of the body there grow out slowly 

 hyaline knobs of different sizes, which after a short time are again 

 retracted. 



