1889.] BOTANICAL GAZETTE. IOQ 



below the freezing point at night, and the day was a pleasant one for 

 studying the root-leaves of plants— to me an interesting department of 

 phytology. It was a pleasure to discover a new Pennsylvania locality for 

 Pinus pungens, but a much greater was furnished by a complete carpet of 

 glaucous green leaves of a Corydalis, spread over the moss-covered mass 

 of rotting pine needles under the trees. As the allies of the plant, as 

 known to our botanical grandfathers, died completely down in winter, 

 why should it be wondered at, and made censurable, that such a plant 



should be dubbed evergreen ? 



Taking a few plants home and subsequently flowering them, it 

 proved to be Corydalis flavida of DC. (Fumaria flavida Rafinesque). I 

 have never met C. glauca in winter excursions, but its near relationship 

 to this species would justify some faith in Cornutus having seen some- 

 thing similar suggestive of the name. 



C. flavida is certainly an annual in the sense of germinating and dy- 

 ing within a twelve month, but in the sense some use the term biennial, 

 that is, getting considerable strength in the autumn after germinating 

 early in the season, and then remaining over to the nest to finish ite 

 growth and mature, it would not be an annual in Curtis's estimation, nor 

 probably would C. glauca be in its native wilds.— Thomas Meehan, Ger- 

 mantown, Pennsylvania. 



Pollen mother-cells.— If any person has experienced difficulty in ob- 

 taining pollen mother-cells in excellent condition for study, their atten- 

 tion is called to the young anthers of Negundo aceroides Moench. Sections 

 of thee* may be easily obtained by cutting across the staminate flowers 

 before they have attained half their full size. When these sections are 

 not too thin the thecse will be found made up of a single whorl or circle 

 of mother-cells, many of which are pear-shaped, due to unequal pressure. 

 The mother-cells in the center of the thecal easily become detached and 

 may be found scattered through the liquid in which the sections are im- 

 mersed. These loose cells have a strong resemblance to the asci of the 

 Erysiphere (powdery mildews), and the four pollen grains may be found 

 in all stages of development. In the beginning there is only the slightest 

 differentiation of the protoplasm into four indistinct masses. As they 

 become more manifest the arrangement of the four is found inconstant. 

 Sometimes they are placed with their longer diameter parallel like the 

 four nutlets in a borrage fruit. In others two are in the same plane and 

 the other two above or below, and at right angles to the first pair. Azo- 

 rubin is excellent in weak solution for bringing out the young grains 

 more prominently. The pollen grains do not use up the thick mother 



bean pod. 



escape 



era 



