2i6 SCIENCE PROGRESS 



the name B. simplex is described by Hazen {Bull. Torrey. Bot. 

 Club, 49, pp. 75-92) from material collected in Norway, and at 

 Cullercoats and Plymouth in this country. In the following 

 number of the same journal (pp. 123-40) Hazen describes two 

 nev/ species of Lobomonas, of which one was collected in Surrey. 



Vol. xlvi. No. 305, of the Jour. Linn. Soc. Bot. is devoted 

 to an account of Berkshire Heleoplankton by Griffiths, and to 

 a description of the Cryptogamic vegetation of New Caledonia. 

 The latter includes descriptions of new species of Hepaticas by 

 Pearson, a new genus of Stigonemaceae by Miss Carter, a new 

 Nitella by Groves, new genera and species of Lichens by Miss 

 Lorrain Smith, and new Fungi by Miss Wakefield. New genera 

 of Mosses are described by Dixon {Jour. Bot., vol. Ix, p. 10 1) 

 of which four are placed in the Funariacese and one in the 

 Hookeriaceae. 



As a supplement to the latter journal. Dr. Watson contri- 

 butes a key for the determination of Lichens in the field. 



General. — ^To the current number of Messrs. Charlesworth & 

 Co.'s Catalogue, Mr. Ramsbottom contributes an excellent 

 summary of the literature on Orchid Mycorrhiza, and incident- 

 ally of the general problem. Attention is called to the antiquity 

 of this type of association found even in the Devonian plants, 

 and the suggestion is made that perhaps ectotrophic and endo- 

 trophic mycorrhiza represent respectively the conditions of 

 fungus parasitic on the phanerogam and vice versa. A very 

 clear account is furnished of the germination process in orchids, 

 and in this connection a tribute is paid to the work of the late 

 Mr. J. Charlesworth. 



Under the title of " Developmental Selection " Bucholz 

 calls attention to the frequency of competition between — ovules 

 within the same ovary, twin embryos, pollen tubes (gameto- 

 phytic selection), male or female gametes. Evidence is brought 

 forward to show that polyembryony is by no means uncommon 

 in Ferns, Gymnosperms and Angiosperms, which may well 

 indicate a widespread gametic selection. Pleurality of embryos 

 has also been shown to occur in the gametophytes of Lycopo- 

 diales and Equisetales. Such developmental competition is 

 calculated to bring about the survival of the gametes and 

 embryos most fitted for the uniform environment of the parent, 

 and thus extends the concept of natural selection to the earliest 

 phases of development {Amer. Jour. Bot.). 



PLANT PHYSIOLOGY. By Prof. Walter Stiles, M.A., Sc.D., 



University College, Reading (Plant Physiology Committee). 



Flower and Fruit Formation.— -While the physiology of the 

 vegetative body of the plant has received very great attention 



