CLEAVAGE OF LEPIDOSIREX 499 



first furrow is not strictly meridional but is displaced outwards 

 some little distance from the abapical pole. 



On the whole tlie evidence of the seven eggs obtained of this 

 stage goes to indicate that the normal procedure of the egg of 

 Lepidosiren is that the first meridional furrow is com- 

 pleted before the second furrow at right angles to it begins to 

 make its appearance. 



Stages 3-4. — Five eggs belong to the commencement of 

 this period during which the egg is normally sub-divided by the 

 completion of the first and second meridional furrows into four 



Text-fig. 3. 



a. Apical view. h. Abapical view. 



approximately equal parts, and the third set of furrows — 

 vertical — make their appearance. In two eggs out of the five 

 the first and second meridional furrows are alone present and 

 perfectly normal. Two other eggs exhibited a feature men- 

 tioned in an earlier stage, the continuity of the furrows being 

 very faintly marked and in some places quite obliterated. 

 In one of the two eggs one of the furrows in the region of the 

 apical pole shows quite faintly marked ; in the other egg 

 (Text-fig. 3) in which neither the first nor the second furrows 

 had quite reached the abapical pole, the continuity of the 

 first meridional furrow is broken at one side and again at the 

 abapical pole. 



The last specimen of this particular stage shows the tendency 



Ll2 



