THE ENDOSPERM 



251 



An interesting deviation, which is of a very different nature from 

 those described above, occurs in Hyoscyamus niger (Svensson, 1926). 

 Here the first division of the primary endosperm nucleus takes place 

 in the vicinity of the egg, so that the chalazal chamber is the larger. 

 In the micropylar chamber either four to eight free nuclei are pro- 

 duced before cell formation takes place, or at first there are two 

 longitudinal walls and then some irregular divisions resulting in a 

 small mass of cells. In the chalazal chamber there are repeated 



Fig. 142. Development of endosperm in Monochoria. A-F, diagrams showing 

 stages in development of endosperm. G, M. vaginalis; chalazal chamber is uninu- 

 cleate and micropylar is binucleate. (After Ono, 192S.) H, more advanced stage, 

 showing four nuclei in micropylar chamber and two in chalazal. (After Julianj, 

 1981b.) I, M. korasakowii; initiation of lateral haustoria from micropylar cham- 

 ber. J, M. vaginalis, haustorium visible on one side only. K, M. korsakowii, 

 haustoria in advanced stage of development. L, cross section of ovule, passing 

 through haustoria. (After Ono, 192S.) 



