266. SUMMAKY OF CURRENT RESEARCHES RELATING TO 



gametophjte of Pseudotsuga, but, in contradistinction to this genus, only 

 those pollen-grains which reach the nucellus develop pollen-tubes. 

 Fertilization is normal, but the relative sizes of the two male nuclei 

 were not determined. The pro-embryo is of the Abietinean type, and 

 one embryo is the rule. The author concludes that there is a distinct 

 natural affinity between Larix and Pseudotsuga. A. B. E. 



General. 



Fossil Higher Plants from the Canal Zone. — Ed. W. Berry 

 {U.S. National Museum, Bulletin 103, 1918, 15-44, 7 pis.). The 

 author describes seventeen species of plants, nearly all of which are new, 

 from the Oligocene series of Panama. The plants include ill-defined 

 fragments of one fern, two undetermined species -of palm represented 

 by fragments of foliage, and a third represented by petrified stems ; and 

 sixteen Dicotyledons, two of which are represented by fruits and the 

 remainder by leaves. The Dicotyledons represent fourteen families, 

 which are also characteristic of the existing flora of the Isthmian region. 

 The Tertiary plants indicate an abundant rainfall and relatively high 

 equable temperatures, such as prevail at the present time in the hill 

 country and coastal plain of the Isthmus. There is no indication of 

 upland vegetation or any trace of the characteristic vegetation of low 

 muddy shores. The bulk of the fossil plants clearly belong to the ever- 

 green rain-forests, and have the appearance of having been washed into 

 the basins of sedimentation by streams. A. B. R. 



Grasses of Illinois.— Edna Mosher {University of Illinois, Agri- 

 cultural Experimental Station, Bulletin 205, 261-425, 287 figs.). A 

 useful working monograph of all the grasses which have been recorded 

 for the State of Illinois based on a thorough examination of earlier 

 records and available herbarium material. Mosher admits 204 species, 

 over one-fifth of which are now recorded for the first time as occur- 

 ring in the State. A brief account of the general structure of grasses 

 is followed by an elaborate key to the genera. Adequate descriptions 

 are given of the genera and species, and where the genus contains more 

 than one species keys are included as aids to determination ; the illustra- 

 tions are numerous and helpful. The arrangement of the genera follows 

 that of Gray's " Manual of the North American Flora " ; the species 

 follow alphabetically under each,genus. A. B. R. 



Regional Spread of Moisture in the Wood of Trees. — Wm. G. 

 Craib {Notes from Royal Botan. Gard. Edinhurgh, 1918, 11, 1-18, 

 10 pis.). In the present communication the author deals with 

 deciduous-leaved trees during the period late autumn to early spring. 

 Working with specimens of sycamore {Acer Pseudoplatanus) which were 

 felled and examined at several periods between October and March, the 

 following facts and conclusions are formulated. With the cessation of 

 foliar activity for the season, the tree immediately begins its prepara- 

 tions for the next season. The first phase is the storing up in the centre 



