38 Morphologie, Teratologie, Befruchtung, Cytologie. 



formly thin-walled or interspersed with a few stereids. The herba- 

 ceous Stern increases very little in thickness, and beyond the for- 

 mation of secondary mestome-strands no other secondary tissues 

 were observed. Much attention is given to the interfascicular tissues 

 which appear to develop independently of the pericj^cle, especiallj' 

 the libriform. Characteristic of the leaf-blade is the palisade-tissue 

 of very low cells, and the open pneumatic tissue. Phryma represents 

 a truly sciaphilous type. Theo Holm. 



Kelly, R., Observations on the function of Acacia 1 e a f 

 glands. (Victorian Naturalist. XXX. 7. p. 121-127. 1913.) 



Observations on the living plants have led the author to con- 

 clude that these so-called glands (for which he suggests as more 

 appropriate the name of vents) perform excretor}'^ functions and are 

 capable of performing them without outside aid and that they are 

 strictly speaking neither glands nor nectaries. The secretions are 

 neither fluid nor viscid. W. G. Craib (Kew). 



Mc Allister, On the cj'tology and embryolog y of Smi- 

 lacina racentosa. (Trans. Wisconsin Acad. Sei., Arts a. Letters. 

 XVII. p. 599—660. pl. 56—58.) 



The author differs from Lawson (The Phase of the Nucleus 

 Known as Sj'napsis. Trans. Roy. Soc. Edinburgh. Vol. XL VII. p. 

 591 — 604. pl. 1—2. 1911), who reported that synapsis is due, not to 

 a marked contraction of the nuclear contents, but to a sudden 

 enlargement of the nuclear cavity, which gives the appearance of 

 a contraction. 



Mc Allister Claims that synapsis is really due to a contraction 

 and not to any considerable enlargement of the nuclear cavity. 



During synapsis there is a lateral pairing and fusion of parental 

 spirems, the fusion being complete at the time of recover}^ from 

 synapsis. After this recovery, there is a second contraction stage. 

 The double heterotypic chromosomes are formcd, not bj'^ the ap- 

 proximation of the limbs of loops, but by the transverse segmenta- 

 tion of a longitudinally split spirem, the line of the split probably 

 representing the line of approximation of the two parental spirems 

 Seen at synapsis. 



The heterotypic and homotypic mitoses in the megaspore mother 

 cell result in the formation of four megaspores, separated by plasma 

 membranes. The membrane formed at the heterotypic mitosis per- 

 sists, while those formed at the homotypic mitosis quickly disappear, 

 thus leaving two binucleate cells. From the inner binucleate cell, 

 an eight-nucleate embryosac is developed. Consequently, two mega- 

 spores take part in the formation of the embryosac. 



Adventitious embryos develop from nucellar cells in the micro- 

 pylar region and some of these embryos become mature. The pre- 

 sence of pollen tubes indicates that embryos may also result from 

 fertilization. Charles J. Chamberlain (Chicago). 



Pace, L., Two Species of Gxrostachys [Spiranthes]. (Baylor Univ. 

 Bull. XVII. p. 1 — 16. pl 1. 1914.) 



The origin and development of the embr3'osac of Gyrostachys, 

 more commonly known as Spiranthes, is described for two species, 



