June, 1909.] Reduction Division in Hyacinthus. 539 



THE REDUCTION DIVISION IN THE ANTHERS OF 

 HYACINTHUS ORIENTALIS.* 



Edith Hyde. 



There are many problems in connection with the reduction 

 division, which have not been satisfactorily solved. It was, 

 therefore, determined to take up the problem on some plant 

 which would show the nuclear structures as distinctly as possible. 

 The plant finally selected for the investigation was the common 

 hyacinth, Hyacinthus orientalis L. 



The dry bulbs of the common hyacinth were planted in the 

 greenhouse at various intervals during the Fall of 1907. A 

 bulb was opened and examined almost every day, but it was not 

 until the first week in November that the desired stages were 

 secured, since it was some time before it was ascertained how 

 long the dry bulbs must remain in the ground before reduction 

 begins. This depends entirely on the time of planting. If the 

 bulbs are put in the ground early in the fall it will be some time 

 before reduction takes place. The desired stages were finally 

 secured in bulbs which were planted in the last week of October, 

 and which remained in the ground less than a week, showing 

 that slow development takes place in the bulb while in the dry 

 state. All of the material killed on the days from the 1st to the 

 4th of November showed the various reduction stages, and even 

 in the individual bulb nuclei ranging from early microsporocytes 

 to tetrads were found. The usual methods of killing and 

 imbedding were used and the sections were cut from 10-12 mic. 

 thick. The slides were stained most satisfactorily with Delafield's 

 Haemotoxylin. This study was begun under the direction of 

 Prof. R. F. Griggs and was completed under Prof. J. H. Schaffner, 

 to both of whom the writer is greatly indebted for kindly assist- 

 ance and suggestions. 



In the younger anthers many nuclei were found showing the 

 last division previous to the formation of the microsporocytes 

 (figs. 1, 2). In these nuclei the spirems showed a linin thread 

 with definite granules. There is evidently no long resting stage 

 in the sporocyte previous to reduction and this makes it difficult 

 to recognize the young sporocytes from their mother cells, the 

 two being present in the sporangium at the same time. A 

 tendency toward indefinite massing of the chromatin (figs. 3, 4) 

 in the early sporocytes, gradually disappears as the threads of 

 the network become more prominent (fig 5). There does not, 

 however, seem to be any definite massing of the chromatin into 



* Contributions from the Botanical Laboratory of Ohio State Uni- 

 versity, XL VI I. 



