RECENT ADVANCES IN SCIENCE 307 



embryo and seedling of grasses, which appears likely to open up 

 new lines of work on the evolution of the Monocotyledons 

 from a lily-like type derived in turn from some ancestral butter- 

 cup-like type ; these authors find that, although the compli- 

 cated anatomy of the grass seedling renders comparison with 

 the seedlings of other Monocotyledons difficult, all the varia- 

 tions found can be derived from a hypothetical type the vas- 

 cular skeleton of which is that of a hypogeal Monocotyledon 

 showing remarkable similarity to that of the Zingiberaceae. 

 The paper is illustrated by a large number of remarkably clear 

 figures which, together with the skilful manner of presenting 

 the facts, makes it easy to follow the somewhat intricate de- 

 tails described. In two papers published almost simultaneously 

 Willis (Ann. Bot. 29, Journ. Linn. Soc. Bot. 43) deals with 

 various structural and biological features of the Podostema- 

 ceae, a remarkable family of tropical aquatic plants in which 

 the functions of stem and leaves are assumed by the roots ; 

 the author proposes the separation of certain genera as a 

 new family (Tristichaceae). 



ZOOLOGY. By C. H. O'Donoghue, D.Sc, University College, London. 



Protozoa. — The life histories of a number of protozoan forms 

 both free-living and parasitic are dealt with in various papers. 

 Heron-Allen records a long series of investigations into the 

 reproductive processes and the Economics of some of the 

 Foraminifera that have occupied some years (Phil. Trans. Roy. 

 Soc. B. June 191 5). Together with Earland he also publishes 

 the second part of a large monograph on the Foraminifera from 

 the Kerimba Archipelago in Portuguese East Africa in which 

 thirty-two new species are treated (Trans. Zool. Soc. April, 

 191 5). Pixell-Goodrich has reinvestigated the life history of 

 sporozoa living in Spatangoids, named Lithocystis schneideri, 

 and has identified five separate species (Quart. Jour. Micro. 

 Sci. vol. lxi., May 191 5), and also shown that Minchinia 

 chitonis,a. parasite of the molluscchiton,is undoubtedlya Haplos- 

 poridian, and not a coccidian as was previously thought (Proc. 

 Zool. Soc. May 191 5). Mackinnon has added a third part 

 to her studies on parasitic protozoa concerning Embadomonas 

 obtained from trichopterous larvae and a Trichomastigine 

 multiplication cyst (Quart. Jour. Micro. Sci. vol. lxi. May 

 1915). The parasites of mice form the subjects of two papers. 



