and Laboratory Methods. 1381 



CURRENT BOTANICAL LITERATURE. 



Charles J. Chamberlain. 



Books for review and separates of papers on botanical subjects should be sent to 



Charles J. Chamberlain, University of Chicago, 



Chicago, 111. 



REVIEWS. 



Murbeck, S. Ueber das Verhalten des Pollen- Since Other species of Alchemilla have 



schlauches bei Alchemilla arvensis und das been found by the same writer to be 



Wesen der Chalazogamie. Lunds Univer- ^, .. •. .„ r • .„ ^4. <_„ „„4.^ 



sitets Arsskrift. 36: T-19, pis. 1-2, .901. parthenogenetic, it is of interest to note 



that A. arvensis has a pollen tube at 

 all. In the development of the ovule a micropyle is formed, but long before 

 pollination occurs the continued growth of the integument entirely closes the 

 micropyle. The pollen tube grows down through the style and enters the ovule 

 at the chalazal end, then traverses the entire length of the integument, growing 

 through the tissue, and enters the micropylar region of the sac. Although the 

 act of fertilization was not observed, it may be reasonably assumed to take place 

 in spite of the fact that other species of Alchemilla are parthenogenetic. In this 

 case the pollen seems perfectly normal. The author does not regard this as a 

 case of chalazogamy such as is found in Casuarijia, Corylus, Carpimis, Betiila, 

 Alnus, and /iigla?is, but rather as a type intermediate between genuine chalazo- 

 gamy and the condition found in Ulmus. Chalazogamy is regarded as a derived 

 condition, and as a physiological phenomenon of no phylogenetic significance. 



c. J. c. 



Brand, F. Bemerkungen Uber Grenzzellen und The heterocysts of the NastOCacea^ 

 liber spontanrothe Inhaltskrirper der Cyano- have been described as cells poor in 



phycecc. Ber. d. deutsch. bot. Gesell. 19: ^ ^ -^i 1 ^ ^ ^ 



j^j. Qj contents, or with only watery contents, 



and they have been supposed to be 



concerned only in false branching and in breaking filaments up into hormogonia. 



The present writer, in investigating Nostoc convnniie, finds that in addition to the 



empty heterocysts there are also heterocysts with contents, which are not watery 



but elastic, and of considerable consistency. By pressure on the cover-glass, the 



walls of these heterocysts may be broken and dissociated from the contents 



which retain their spherical form. It was found that the contents divide like 



ordinary vegetative cells, and give rise to filaments. It was also found that in 



some cases the contents of the heterocyst pass over into the neighboring cells, 



and may induce in them a renewed activity. The writer believes that the red 



granules of the Wasserbliithe, forming members of the Cyanophyceae, are rot 



due to gases. c. j. c. 



Ernst, A. Beitrage zur Kentniss der Entwicke- This paper treats in considerable detail 

 lung des Embryo-sackes und des Embryo the life history of Tlilipa Gesneriaua, 

 (Polyembrvonie) von Tulipa Gesneriana L. , . , ^, , . , 



Flora. 88: 37-77, pis. 4-8, 190 1. ^""^^ ^^^ appearance of the archesponal 



cell in the nucellus of the ovule up to 

 the ripe seed. Besides the original work, there is a very convenient summary of 

 the literature of polyembryony. A few of the points noted are the following : 



