296 The Microscope. 



last, the constriction takes place at the equator, or a cell-plate 

 forms there, and the polar crowns are soon changed into the two 

 new nuclei of the two cells as the result of the division. 



Thus we see there are two phases in each processs of division. 

 The first goes as far as the formation of the equatorial ci-own, 

 the culminating point of kinetic division ; this is called pro- 

 phase by Strasburger. The second phase comprises the disloca- 

 tion of the equatorial crown and the reconstitution of the two 

 nuclei ; it includes the metaphase and anaphase of Strasbur- 

 ger. There is no need of applying new and technical terms to 

 these different processes as Plemming has done, but common 

 language is sufficient for the purpose. 



From what I have said, I conclude that cytodieresis comprises 

 both caryodieresis and plasmodieresis ; i. e., the division of the 

 nucleus and that of the cell-protoplasm, and that both are effected 

 b}^ certain movements which result in certain kinetic figures, 

 familiar to every student of Cytology. 



Space does not allow me to enter into details, but I hope to be 

 able to publish soon in the pages of The Microscope some spe- 

 cial observations which may be easily repeated by even the ama- 

 teur microscopist, who thus may gain a fair knowledge of that 

 most difficult problem of Cytologj' — cell-division. 



Here I must thank my readers for the patient hearing they 

 have given me. I cannot flatter myself that I have added any- 

 thing new to science, but it will be a satisfaction to me if I have 

 opened only a pathway in this department of scientific research 

 for some of the readers of The Microscope. 



(the end.) 



EMBEDDING AND SECTIONING MATURE SEEDS. 



W. W. ROWLEE. 

 READ BEFORE THE AMERICAN SOCIETY OF MICROSCOPISTS. 



THE modifications that may be made of the paraffin method of 

 embedding objects for sectioning are very many. There is 

 always some danger, however, of shrinking delicate and very 

 soft plant tissue. This is due to the use of heat in the process 

 pf infiltration; and, probably, some of the non-heat-employing 



