THE DEVELOPMENT OF THE POLLEN OF SARRACENL\ 



M. Louise Nichols 



(with plate v) 



During ]\rarch 1907, through the courtesy of Dr. J. M. Mac- 



ANE 



fine 



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versity of Pennsylvania. The species examined were S. 

 purpurea^ 5. variolariSy 5. riibra^ and 5. psitlacinay besides the hybrids 

 S. flava X variolaris and S. flava X purpurea. A close similarity 

 prevails in the pollen of the different species, nor does any marked 

 difference appear in the hybrids. Abnormahties of division among 

 the latter are practically absent. 



The material consisted of flower buds fixed in chrom-acetic acid. 

 Thin sections of the anthers were stained by the iron-hematox}'lirL 

 method and with safranin and malachite green. 



The nucleus of the pollen mother cells contains an intensely stain- 

 ing nucleolus surrounded by a clear space. ^Vith safranin and mala- 



green 



sm 



(fig 



1) does not stain deeply, and shows a trace of fibrillar structure 

 i). The approach of the synapsis stage is indicated by a marked 

 apparently rather sudden gro\\-th in size of the nucleus. The 

 ;olus also becomes larger, and the clear space surrounding it less 

 defined but wider. The linin shows more definite indications 



2). A few deenlv stainin.s; granules now appear 



of a network (fig. 2). A few deeply staining 

 within the linln ; these increase m number as the network de^ 

 (fig- 3)' Occasionally granules can be seen in close proximity 

 nucleolus (fig. 3), which become larger and irregular in shape 



and 



(fig^ 



sometimes 



masses 



paks of chromatin clumps. Thus in fig. -4 there 

 of chromatin, one on each side of the nucleolus 



of about the same size; while farther remo 

 there are two others, smaller than the first, 1 

 other in size. Similar relations are seen in fig 



31I 



nucleolus 



akal Gazette, ▼ol 



