BOT.-VOL. I.] LAWSON—COBMA SCANDENS. 171 



two groups and then fuse to form a bipolar spindle. No 

 bodies or granules that could be identified as centrosomes 

 were observed in any stage of the process. 



It seems very improbable that the occurrence of multi- 

 polar figures is an abnormal phenomenon. They have 

 been found to occur in Liliuni by Farmer (1893), in Larix 

 by Belajeff (1894), and Strasburger (1896). They have 

 been found in Lilium, Fritillaria, Helleborus, Podophyllum, 

 and Piniis by Mottier (1897, a and b), in Henierocallis by 

 Juel (1897), in Chara by Debski (1897), and in Zamia by 

 Webber (1897.) The writer has observed them in He&- 

 ferloe, Hedera, Disporum, S?mlactna, Gladiolus, Iris, 

 CobcBa, and other genera. From this we can only conclude 

 that multipolar spindles are of very general occurrence, and 

 this throws considerable doubt upon the existence of cen- 

 trosomes in the higher plants. 



It must be observed, however, that in all cases where 

 multipolar figures have been described, very little has been 

 observed upon the very earhest stages in the development 

 of the kinoplasmic fibres. It is with the hope of throwing 

 some light on these stages that the following observations 

 upon the pollen-mother-cells of Cobcea scandens have been 

 made. 



About two years ago Mr. Osterhout suggested that the 

 writer undertake some investigations upon spindle-forma- 

 tion in anthers of different orders of flowering plants. 

 In undertaking such a task it is very desirable to obtain 

 material with large anthers and large pollen-mother-cells as 

 well as large nuclei. The anthers of Cobcea are very good 

 in all of these respects. 



The anthers were gathered and immediately fixed in the 

 field. The following fixing fluids were used: 



Alcohol, 95 per cent. 



Chromic acid, i per cent. 



Flemming's mixture, chromic-osmic-acetic, strong solution. 



Wilson's sublimate-acetic. 



Boveri's picro-acetic. 



Corrosive sublimate, saturated solution in 95 per cent, alcohol. 



