184 BOTANICAL GAZETTE [march 



and Strasburger. Avoiding an unnecessary repetition, a few points 

 concerning the centrosome and chromosomes may be noted. 



The resting nucleus of the discharged egg has shown no mani- 

 festation of polarity. Cytoplasmic alveolar structures as well as 

 plastids, and spherical globules of various sizes are arranged radially 

 about the nucleus. The cvtOD 



asm 



brane has a finely granular aspect. When the sperm has entered 

 the protoplast of the egg and is advancing toward the egg nucleus, 

 a change occurs in the latter. At a certain spot outside the nuclear 



kinoplasmic 



membrane. 



ery 



formed 



rounding this centrosome (figs. 68a, 68b). The egg nucleus, there- 

 fore, is furnished with a single centrosome before the sperm reaches 

 it. The second centrosome has been found to appear in connection 

 with the sperm. 



While the sperm is proceeding toward the nucleus, there appear 

 numerous irregularly crowded granules, surrounding the nuclear 



membrane. 



very 



from that of the centrosome of earlier occurrence, but they rapidly 



(sometimes) 



Their 



growth, thus, is different from that oi 



granules of the same size as young centrosomes can be distinguished 

 from genuine centrosomes. Such is the condition of the region sur- 

 rounding the nucleus just before the appearance of the second centro- 

 some. The sperm then reaches the egg nucleus, becomes close! 

 a ? pU ? d t0 it ' and seems t0 sli P in through the nuclear membrane 



instant, there is first observed a new centro- 

 pearing at the spot where the sperm entered. 



(fig 



ery 



m 



the sperm, as was suggested bv Strasburger (24) ■ 0r lt 1S 



e nucleus migw 

 streaming move- 



ment of kinoplasm caused by the progress of the sperm. At any 



first 



entrance of the sperm, and the second an: 

 entry. That the appearance of the seco 



ind 



