Marquette, Manifestation of polarity in plant cells which usw. 297 



closely against tlie imcleus, in some cases at one end of the 

 somewhat elongated nucleus. Frequently the elaioplast lies so close 

 to the imcleus as to deform it. There are few data relative to 

 the behavior of the elaioplasts during auclear division. According 

 to Raciborski 1 ) tliey play no part whateverin it; he also maintains 

 that they are formed de novo in the cytoplasm. 



I may note in this connection a polar Organization during 

 synapsis which 1 have observed in two other of the highei 

 Pteridophytes and which requires further study. If spore-mother- 

 cells of Equisetum hyemale are examined during the synapsis stages 

 it is seen that a more or less sharply bounded mass lies in the 

 cytoplasm at one siele of the eccentrically placed nucleus. This 

 mass consists of numerous closely packed granules, largely starch, 

 of varying sizes which frequently show an affinity for orange if 

 stained with the triple stain. Upon this mass well developed 

 cytoplasmic rays are centered (flg. 8) so that the figure has a 

 striking resemblance to an archoplasmic region with radiations 

 proeeeding from it, as known for various animal cells. 2 ) The spore 

 mother cells of Equisetum are usually distinctly elongated at the 

 time of synapsis, the nucleus almost invariably lying at one end of 

 the cell. The chromatin is aggregated at the side of the nucleus 

 nearest the cell wall. Just as regularly the dense aggregation in 

 the cytoplasm lies on the side of the nucleus opposite the synaptic 

 mass. These relations stand out strikingly in cells which, after 

 flxation in osmic aeid mixtures, are teased out of the spore sacs 

 and examined whole. The relation is just the reverse of that 

 obtaining between synaptic mass and centrosome in animal cells. 

 Here, as has been frequently figured, 3 ) the chromatin is aggregated 

 on the side of the nucleus next to the centrosome. 



I have observed a similar definite orientation of the synaptic 

 mass in the spore mother cells of Marsilia quadrifolia. These cells 

 also show a more or less sharply defined dense mass in the 

 cytoplasm at one side of the nucleus consisting largely of small 

 starch grains, and here the chromatin is regularly aggregated on 

 the side of the nucleus adjacent to the mass of starch grains. 

 (Fig. 9.) I have not worked out in detail the further history <>f 

 these aecumulations in either E<piüetum or Marsilia and am not 

 in a position to say whether they are related to each other or 

 what their relation is, if any, to the polar struetures of Isoete*. 



But it is not only in these more or less isolated cases that 

 \ve have evidence of a polar Organisation of the higher plant cells. 

 All the higher plants during at least one stage of their life 

 history show such an Organisation of their cells before any 



') Raciborski. IL: Über die Entwicklungsgeschichte der Elaioplasten l"-i 

 Liliaceen. (Bull, inter. d. l'acad. d. Sei. de. Craeovie. 1893. p. 259.) 



2 ) Hermann: Arch. mikr. Anat. Bd. XXXVII. PI. XXXI. 



s ) See for example Farmer, .1. B. and Moore, J. E. S. The maiotic phase 

 in animals and plants. (Quart. Jour. Micros. Sei. Vol. 48. PI. XL Fig. 72) and 

 Schreiner. A. und K. E. Über die Entwickeluno- der männlichen Geschlechts- 

 zellen von Myxine glutinosa. (Arch. de. Biol. T. XXI. Figs. ö2. 71. 170 etc.) 



