Morphologie, Befruchtung, Teratologie, Cytologie. 327 



scheinlich hat man es hier zu tun mit Schutzmitteln gegen die Tier- 

 welt des Erdbodens. 



Auch hat Verf. Beobachtungen gemacht über die Mykorrhizen. 

 Von allen untersuchten Pflanzen erwies sich nur Eugenia als pilzfrei. 

 Die Mykorrhizen waren alle endotroph. Die Fragen, welche sich hier 

 vortun, besonders nach der Natur des Pilzes können definitiv nur an 

 lebendem Material entschieden werden. Jongmans. 



Chaniberlain, C. J., The ovule and female gametophyte of 

 Dioon. (Botan. Gazette XLII. p. 321-358. pls. 13—15 Nov. 1906. 



In this first of a series of papers on the morpholog}^ of Dioon 

 the author discusses 1) Dioon in the field, 2) material and methods, 

 3) megasporophylls and ovules, and 4) the female gametophyte. This 

 Mexican cycad has a height of about a metre, and may attain an 

 age of a thousand years or more. The ovulate cones are verj" 

 large, common!}" weighing 5 Kgm., and consist of numerous furry 

 sporophylls which are somewhat leaf-like and bear two ovules, each 

 provided with three integuments, an outer fleshy, a stony, and an 

 inner flesh3\ These probably represent two fused coats, though it is 

 not certain where the union has taken place. The nucellus is separate 

 from the integument for only a short distance, and in the nucellus 

 a pollen-chamber is excavate'd in the usual way. At the base of the 

 ovule is an abscission layer provided with a central papilla. The 

 megaspore membrane is of average thickness, and consists of two 

 la^'^ers, the outer one being made up of club-shaped bodies. From 

 one to ten archegonia are produced, each having a two-celled neck 

 and a ventral-canal nucleus. The &g^ first absorbs food in the ordi- 

 när}' way, but later puts forth haustorial projections into the jacket- 

 cells. The nucleus of the ^g'g is very large and contains twelve 

 chromosomes, but its structure in the resting condition is not yet 

 interpreted. M. A. Chrysler. 



Cook, M. T., The embrvogenv of some Cuban Nymphaeaceae . 

 (Bot. Gaz. XLII. p. 376— 392T pls. 16—18 Nov. 1906.) 



The representatives studied present a uniform method of forma- 

 tion of the embryo-sac, showing the peculiar feature that the 

 antipodal end is produced into a tube or sac, which penetrates the 

 nucellus and contains one of the nuclei produced by the division of 

 the endosperm nucleus. The function of this tube appears to be the 

 transferring of food from the nucellus to the endosperm, whence it 

 is supplied to the embryo. In the embryo of species of Nymphaea 

 and Castalia a collar-shaped cotyledonary ridge is formed, extending 

 from two-thirds to almost completely around the embryo, and on 

 this two cotyledonary lobes are produced. From this fact and from 

 the similarity in the early stages of endosperm formation to that 

 observed in Sagittaria and Liumocharis the author concludes that 

 the Nymphaeaceae should be classed as anomalous monocotyledons. 



M. A. Chrysler. 



Hus, Henri, Fasciation in Oxalis crenata and experimental 

 production of fasciation s. (Report Missouri Bot. Garden XVII. 

 p. 147—152. pls. 17-19. 1906.) 



Experiments with Oxalis crenata and other plants yield support 



