262 



SCIENCE 



[N. S. Vol. XXXIII. No. 842 



also, is controlled by the prevailing warm winds 

 irom the western ocean; at the coast line snow is 

 seldom seen. 



Under such an equable climate and abundance 

 of rainfall, the peninsula, with few exceptions, is 

 the most densely forested region in our country; 

 and smaller plants do equally well. Of course as 

 one approaches the mountains the forest becomes 

 less dense till the timber line is reached; but in 

 the reverse proportion the flowering herbs at the 

 same time increase in number and beauty. The 

 region in the lower levels is a jungle of trees, 

 shrubs and entangled vines. 



About 200 square miles of the timbered area 

 has been burned over; 260 square miles is nat- 

 urally timberless, lying just at timber line; and 

 150 square miles consist of ice and rocks. 



The most conspicuous plants of the peninsula 

 are red fir {Pseudotsuga taanfolia) , lovely fir 

 (AHes amahihs) , subalpine fir (Ahies lasio- 

 carpa) , white pine (Pimus monticola) , red cedar 

 (Thuja pUcata) , Alaska cedar (Ohamcecyparis 

 nootkatensis ) , Sitka spruce ( Picea sitchensis ) , 

 Merten's hemlock ( Tsuga Mertensiana ) , vine 

 maple (Acer cirdnatum), maple (Acer macro- 

 phyllum), alder (Alnus oregona) , cottonwood 

 ( Populus trichocarpa ) , dogwood ( Gornus Nut- 

 tallii) , thimble berry (Rubus parviflorus) , salmon 

 berry (R. speotabilis ) , raspberry (R. leuco- 

 dermis], red elderberry (Samliucus callicarpa), 

 red huckleberry ( Yacdnium parvifoUum) , salal 

 (Gaultheria shallon) , Oregon grape (Berberis 

 nervosa), fireweed (Epilobium spicatum) , bracken 

 fern ( Pteridium ) , blue huckleberry ( Vaccinium 

 ovalifolium) and devil's club (Echinopanaai hor- 



Of the plants of the region, the most conspicu- 

 ous are the forest trees, which here reach gigantic 

 proportions. Principal among these are fir, 

 spruce, hemlock and cedar ranging from 200 to 

 400 feet in height, 80 feet clear of limbs, and 

 from 10 to 13 feet in diameter, or more (the 

 cedars ranging from 30 to even 50 feet in some 

 instances ) . Intermingled with these trees is a 

 profusion of shrubbery so dense in the coast dis- 

 tricts that it is difficult to traverse the region. 

 The estimated timber aggregates more than 70,- 

 000,000 M. feet B.M., or enough timber to supply 

 the entire United States's demand for more than 

 two years. 



The plants so far identified in the peninsula 

 number 689. 



Tvyin Hybrids in (Enothera, with a Suggestion 

 concerning their Explanation: R. R. Gates. 



A large number of crosses were made, confirm- 

 ing in general the type of behavior in (Enothera 

 called by de Vries twin hybrids, and adding new 

 crosses which have not previously been made. 

 When a member of the Onagra group of species of 

 (Enothera is pollinated by 0. Lamarckiana or 

 one of its mutants, two types are produced known 

 as tefo. and velutina, the former having broad 

 and smooth leaves, the latter narrow, furrow- 

 shaped and hairy leaves. These types resemble 

 each other in the different crosses, and both 

 usually breed true. There is a similar dimorph- 

 ism in cultures of 0. Uevifolia, broad-leaved and 

 narrow-leaved types occurring. In cultures of 

 forms which probably belong to 0. muricata 

 (having smaller flowers than 0. biennis), from 

 wild seeds collected in Nova Scotia, at St. John, 

 N. B., and at Winnipeg, a similar dimorphism is 

 found to occur,' i. e., broad-leaved and narrow- 

 leaved types, although the races do not all agree 

 in other particulars. The Winnipeg plants came 

 from seeds of one individual. There is therefore 

 a marked dimorphism of some of the forms in the 

 wild condition, and this may account for the 

 occurrence of similar twin types in crosses in 

 which 0. bienms is the female parent, the condi- 

 tion being transmitted in the eggs, but not usu- 

 ally through the pollen. 

 The Sand-dune Flora of Iowa: B. Shimek. 



A discussion of the distribution and the physi- 

 ographic features of the limited dune areas of the 

 state is given. The flora of the sand dunes is 

 presented and the fact is brought out that while 

 a limited number of species may be considered 

 as characteristic of the dunes, the greater part 

 of the flora is identical with that of the drier 

 prairies. 



On the Relation of the Living Cells to Transpira- 

 tion and Sap- flow m Gyperus: James Bertbam 



OVEKTON. 



Experiments in which cut stems of Gyperus are 

 placed in water show that withering occurs sooner 

 than when a certain portion, not to exceed 20 cm., 

 has been killed with steam and the killed stems 

 left in connection with the roots. When 20 cm. 

 of the stem are killed with steam the leaves 

 wither in about eight days, or in about the same 

 time as control plants. It has been found that 

 the longer the portion killed by steam the sooner 

 the leaves above wither and dry. When 25-30 cm. 

 of the stem are killed with steam, the leaves 

 wither in three to five days, no matter how long 

 the section killed with steam may be. The leaves 

 on steamed stems never wither quite so quickly 



