MORPHOCHORETIC PATTERN CLEAVAGE 



337 



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Fig. 29. In vivo metachromasy in eggs o{ Ascidiella scabra. Large grey dots: yolk platelets; 

 black dots : the metachromatic granules ; crossed hatchings : the yellowish plasm (myogenic) ; 

 diffuse cloud, the metachromatic plasm, (a, b) first modifications after fertilization, while 

 maturation proceeds ; the cortical a-granules flow towards the vegetal pole ; (c, d) metaphase 

 and telophase of first cleavage; a lot of granules have been caught in the rays of the asters; 

 (e, f) a two-cell stage; (f) from outside with hyaline droplets expelled in the furrow (e) 

 in optical section; (g, h) young and older tadpole, with granules in the myoblasts and the 

 difTuse plasm in the caudal part of the endoblast (Dalcq, unpublished). 



Literature p. 483 



