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BRIEFER ARTICLES. 



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CHALAZOGAMY IN CARYA OLIVAEFORMIS. 



Nawaschin' announced in 1895 that the pollen tube in /uglam 

 regia does not enter the micropyle, but passes down the ovary wall and 1 



enters the ovule through the chalaza. It was not surprising, there- 

 fore, when in examining some longitudinal sections of pecan fruits I 

 found the chalazal region of the ovules penetrated by pollen tubes. 

 The material was gathered in the spring of 1902, a few days after the 

 withering of the anthers. Though insufficient in amount for embryo- 

 logical work, for which the specimens were primarily collected, they 

 show undoubted evidence of chalazogamy. 



The general morphological character of the ovary wall and ovule 

 resembles that of Juglans as* described by Nawaschin. The placenta 

 nearly fills the lower part of the ovary cavity on two opposite sides, 

 and actually fuses with the ovary wall on the two sides lying in a plane 

 at right angles to the first two. These two regions of fusion, lying on 

 opposite sides of the placenta, correspond to the *'flugelartige Wuch- 

 erungen" of Juglans, and form, as do the "Wucherungen,'* the tissue 

 through which the pollen tube travels to reach the base of the ovule. 

 The single integument tightly encloses the orthotropous ovule. A i 



raicropylar canal is present, but is bent near its upper end, thus bring- 

 ing its aperture into a lateral rather than apical position. No pollen 

 tubes were found entering the canal. 



The course of the fibrovascular bundles from the ovary wall to the 

 ovule is not through the length of the placenta, but transversely 

 through its upper part to a region immediately under the funiculus, 

 at which point they turn abruptly upwards and pass through the cha- 

 laza into the integument. Two bundles enter in this manner from 

 either side through the region of fusion, and then curve so as to 

 approach each other under the funiculus in a plane approximately at 

 right angles to that of the two regions of fusion. Such an arrange- 

 ment leaves the coast clear for the direct passage of the pollen tube 

 from the ovary wall to the funiculus. 



^Nawaschin, S., Ein neues Beispiel der Chalazogamie. Bot. Ceatralbl. 63: 353" 

 357. 1895. 



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