48 SUMMARY OF CURRENT RESEARCHES RELATING TO 
Formation of the Pollen in Magnolia.* * * § — M. L.Guignard points out 
an interesting peculiarity in the mode of formation of the pollen in the 
species of Magnolia examined (M. Yulan , M. Soulangeana, &c.). The 
rule is that in Monocotyledons the first division of the mother-cell 
nucleus is followed by the septation of the latter, the two daughter-cells 
then dividing in the same way ; while in Dicotyledons the first division 
of the nucleus is not followed by the septation of the mother-cell, which 
does not take place until after the second division, between the 4 nuclei 
thus formed. The only important exception to this rule is in the case 
of the Orchidese, which follow the dicotyledonous type. In Magnolia 
we find a process intermediate between the two. After the first division 
of the nucleus, an imperfect septum makes its appearance between the 
two daughter-nuclei, which is very rarely completely formed before the 
second division takes place. 
Anatomy of Orchidese.j — Herr E. Capeder deals with the origin 
and development chiefly of the floral organs, in the following genera and 
species of Orchideae : — Cypripedium, the Ophrydea3, Calanthe veratrifolia, 
Epipactis, Mikrostylis monophyllos, Listera , Neoiiia , Goodyera repens. 
He has determined the interesting fact, that, while in Cypripedium 
calceolus the number of stamen-rudiments is four, in C. barbatum there 
are six, in conformity with the normal monocotyledonous type. The 
author employs the term clinandrium , in a different sense from that of 
some other writers, to define that part of the flower of an orchid which 
lies behind the stamen, and is an outgrowth from its posterior side. Its 
structure can be especially well observed in Listera ovata. Darwin 
describes this part of the flower erroneously as an expansion of the apex 
of the column. 
Structure and Function of Awns.j; — Herr B. Schmid enters in 
great detail into the structure of the awn in grasses, especially in our 
cereal crops. In addition to the biological functions of protection 
against herbivorous animals (which he regards as efficient only to a very 
slight extent), and of dissemination by adhering to the hairy skins of 
mammalia or the feathers of birds, awns answer two important physio- 
logical functions in the life of grasses ; they increase the amount of 
transpiration and the power of assimilation of the plant. These state- 
ments are supported by a number of tables. 
Dimorphism in Curtia.§ — In Curtia tenuifolia, a Brazilian plant 
belonging to the Gentianacese, Herr J. 0. A. Malme records the existence 
of a dimorphism in the flowers (heterostyly), very similar to that in 
Primula. It is the only species of the genus in which this peculiarity 
is known to occur ; in the nearly allied C. tenerrima, possibly only a 
variety of tenuifolia , the stigmas and anthers are always nearly on the 
same level. 
Bog-Plants. || — Herr N. H. Nilsson enumerates all the bog-plants in 
Sweden, and assigns to them the following characters as a class : — 1 The 
* Coinptes Rendus, cxxvii. (1898) pp. 594-6. 
t Flora, lxxxv. (1898) pp. 368-423 (2 pis., 21 figs.). 
t Bot. Centralbl., Jxxvi. (1898) pp. 1-9, 36-41, 70-6, 118-28, 156-66,212-21, 
264-70, 301-7, 328-34 (2 pis.). 
§ Ofv. k. Vetensk.-Akad. Forhandl., Iv. (1898) pp. 305-13 (3 figs.) (German). 
|| Bot. Yer. Lund. See Bot. Centralbl., lxxvi. (1898) p. 9. 
