ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 553 



short-stalked, projecting somewhat above the surface of the substratum ; 

 both kinds contain alsoe and remains of larvas and of nematodes. The- 

 mature bladder (of both kinds) has three mouths, opening into a horse- 

 shoe-shaped funnel, which is in direct communication with the cavity; 

 these are protected by external flaps ; the interior wall of the cavity is 

 furnished with glands and four-armed absorbing hairs. There are only 

 two stamens, with the rudiment of a third and sometimes of a fourth. 



Byhlis gigantea has been erroneously placed in the Droseraceae. 

 The sympetalous corolla, the single integument to the seed, the bilocular 

 ovary, and other characters, show its alliance to the Lentibulariaceae. 

 The glands on the leaves exhibit a close resemblance to those of Pin- 

 guecula. The endosperm puts out remarkable haustoria ; the embryo- 

 sac has the elongated form characteristic of Scrophulariaceae and 

 Lentibulariacete ; there are five stamens of somewhat unequal length; 

 the corolla is regular. 



-o" 



£. Physiology. 

 (1) Reproduction and Embryology. 



Division of Embryo-sac Mother-cells.* — M. Kornicke traces a close 

 resemblance between the processes of nuclear division in the origin of 

 the embryo-sac mother-cells and the corresponding processes in the 

 pollen mother-cells ; the objects observed being species of Iris, Yucca, 

 Carina, and Podophjllum. In neither case is there any reduction 

 division, the reduction in the number of chromosomes being completed 

 before the prophase of the first division of the nucleus of the embryo- 

 sac mother-cell. The two divisions from which the four cells are formed 

 belong to the sam'e type in each case. Variations in the details occur 

 in both processes ; e.g. unequal size of the chromosomes in Yucca ; in- 

 complete separation of a chromosome in the first division in Iris ; 

 S-like curvature of the spindle in Yucca ; its intranuclear origin in 

 Iris pseudacorus. In opposition to earlier statements, the formation of 

 four cells was observed in all the objects, showing a tendency towards 

 the production of tetrads, although the conditions of space necessitate 

 an axial arrangement. The division of the embryo-sac mother-cell in 

 all the plants examined are true tetrad divisions. In Podophyllum 

 peltatum, which often has two embryo-sac mother-cells, the author some- 

 times found each to be surrounded by a peculiar nucellus, both nucelli 

 being enclosed in a common outer integument. 



Embryo-sac of Peperomia.j — Prof. D. H. Campbell supplements his 

 previous account of the peculiar phenomena connected with the process 

 of impregnation by further observations on several species, of which he 

 gives the following summary. 



All species of Peperomia seem to agree in having regularly 16 

 nuclei in the embryo-sac, instead of the normal number of 8. There is 

 no trace of the marked polarity usually observed in Angiosperms. One 

 of the nuclei at the micropylar end enlarges somewhat, and there is an 



* SB. Niederrhein. Ges. Nat. u. Heilkunde, Bona, 1901. See Bot. Ztg., lix. 

 (1901) 2" Abt., p. 186. 



t Ann. of Bot., xv. (1901) pp. 103-18 (1 pi.). Gf. this Journal, 1900, pp. 217, 690. 



